News Listing
December 22, 2023
Affected country: Lesotho
Glide: ST-2023-000261-LSO
From the 22nd - 28th December 2023, most parts of the country received heavy rainfall coupled with strong winds which caused severe damages affecting 190 households (968pp). The impacts of the shocks (heavy rains and storms) were mostly felt by communities mostly in Maseru and Quthing district and lower impact was reported Berea, Mokhotlong, Thaba Tseka. The storm severely damaged businesses and transport networks which hindered full access to essential services such as markets, health services and churches and the situation is expected to worsen in the coming months (January to March) as more rains have been projected by the Lesotho Meteorological Services. The affected families are displaced as their houses were blown away by storms and food stock are also destroyed by rains, as well as some small businesses in the districts. The families opted to seek for shelter with their neighbors and relatives as a temporary solution. (IFRC, 21 Jan 2024)
December 21, 2023
Google released a security update to address a vulnerability in Google Chrome.
December 20, 2023
OpenSSH has released a new version to address a vulnerability in various versions of OpenSSH.
December 20, 2023
Mozilla has published the advisories (MFSA2023-54 and MFSA2023-56) to address multiple vulnerabilities in various versions of Firefox browser.
December 19, 2023
SUMMARY
Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.
The Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA) are releasing this joint CSA to disseminate known IOCs and TTPs associated with the ALPHV Blackcat ransomware as a service (RaaS) identified through FBI investigations as recently as Dec. 6, 2023.
This advisory provides updates to the FBI FLASH BlackCat/ALPHV Ransomware Indicators of Compromise released April 19, 2022. Since previous reporting, ALPHV Blackcat actors released a new version of the malware, and the FBI identified over 1000 victims worldwide targeted via ransomware and/or data extortion.
FBI and CISA encourage critical infrastructure organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of ALPHV Blackcat ransomware and data extortion incidents.
In February 2023, ALPHV Blackcat administrators announced the ALPHV Blackcat Ransomware 2.0 Sphynx update, which was rewritten to provide additional features to affiliates, such as better defense evasion and additional tooling. This ALPHV Blackcat update has the capability to encrypt both Windows and Linux devices, and VMWare instances. ALPHV Blackcat affiliates have extensive networks and experience with ransomware and data extortion operations. According to the FBI, as of September 2023, ALPHV Blackcat affiliates have compromised over 1000 entities—nearly 75 percent of which are in the United States and approximately 250 outside the United States—, demanded over $500 million, and received nearly $300 million in ransom payments.
Download the PDF version of this report:
AA23-353A #StopRansomware: ALPHV Blackcat
(PDF, 477.69 KB
)
TECHNICAL DETAILS
Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 14. See the MITRE ATT&CK Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.
ALPHV Blackcat affiliates use advanced social engineering techniques and open source research on a company to gain initial access. Actors pose as company IT and/or helpdesk staff and use phone calls or SMS messages [T1598] to obtain credentials from employees to access the target network [T1586]. ALPHV Blackcat affiliates use uniform resource locators (URLs) to live-chat with victims to convey demands and initiate processes to restore the victims’ encrypted files.
After gaining access to a victim network, ALPHV Blackcat affiliates deploy remote access software such as AnyDesk, Mega sync, and Splashtop in preparation of data exfiltration. After gaining access to networks, ALPHV Blackcat affiliates use legitimate remote access and tunneling tools, such as Plink and Ngrok [S0508]. ALPHV Blackcat affiliates claim to use Brute Ratel C4 [S1063] and Cobalt Strike [S1054] as beacons to command and control servers. ALPHV Blackcat affiliates use the open source adversary-in-the-middle attack [T1557] framework Evilginx2, which allows them to obtain multifactor authentication (MFA) credentials, login credentials, and session cookies. The actors also obtain passwords from the domain controller, local network, and deleted backup servers to move laterally throughout the network [T1555].
To evade detection, affiliates employ allowlisted applications such as Metasploit. Once installed on the domain controller, the logs are cleared on the exchange server. Then Mega.nz or Dropbox are used to move, exfiltrate, and/or download victim data. The ransomware is then deployed, and the ransom note is embedded as a file.txt. According to public reporting, affiliates have additionally used POORTRY and STONESTOP to terminate security processes.
Some ALPHV Blackcat affiliates exfiltrate data after gaining access and extort victims without deploying ransomware. After exfiltrating and/or encrypting data, ALPHV Blackcat affiliates communicate with victims via TOR [S0183], Tox, email, or encrypted applications. The threat actors then delete victim data from the victim’s system.
ALPHV Blackcat affiliates offer to provide unsolicited cyber remediation advice as an incentive for payment, offering to provide victims with “vulnerability reports” and “security recommendations” detailing how they penetrated the system and how to prevent future re-victimization upon receipt of ransom payment.
MITRE ATT&CK TACTICS AND TECHNIQUES
See Table 1 through Table 3 for all referenced threat actor tactics and techniques in this advisory.
Table 1: ALPHV Blackcat/ALPHV Threat Actors ATT&CK Techniques - Reconnaissance
Technique Title
ID
Use
Phishing for Information
T1598
ALPHV Blackcat affiliates pose as company IT and/or helpdesk staff using phone calls or SMS messages to obtain credentials from employees to access the target network.
Table 2: ALPHV Blackcat/ALPHV Threat Actors ATT&CK Techniques – Resource Development
Technique Title
ID
Use
Compromise Accounts
T1586
ALPHV Blackcat affiliates use compromised accounts to gain access to victims’ networks.
Table 3: ALPHV Blackcat/ALPHV Threat Actors ATT&CK Techniques – Credential Access
Technique Title
ID
Use
Obtain Credentials from Passwords Stores
T1555
ALPHV Blackcat affiliates obtain passwords from local networks, deleted servers, and domain controllers.
Adversary-in-the-Middle
T1557
ALPHV Blackcat/ALPHV affiliates use the open-source framework Evilginx2 to obtain MFA credentials, login credentials, and session cookies for targeted networks.
INCIDENT RESPONSE
If compromise is detected, organizations should:
Quarantine or take offline potentially affected hosts.
Reimage compromised hosts.
Provision new account credentials.
Collect and review artifacts such as running processes/services, unusual authentications, and recent network connections.
Report the compromise or phishing incident to CISA via CISA’s 24/7 Operations Center (report@cisa.gov or 888-282-0870). State, local, tribal, or territorial government entities can also report to MS-ISAC (SOC@cisecurity.org or 866-787-4722).
To report spoofing or phishing attempts (or to report that you’ve been a victim), file a complaint with the FBI’s Internet Crime Complaint Center (IC3), or contact your local FBI Field Office to report an incident.
MITIGATIONS
These mitigations apply to all critical infrastructure organizations and network defenders. The FBI and CISA recommend that software manufactures incorporate secure-by-design and -default principles and tactics into their software development practices limiting the impact of ransomware techniques, thus, strengthening the security posture for their customers.
For more information on secure by design, see CISA’s Secure by Design webpage and joint guide.
FBI and CISA recommend organizations implement the mitigations below to improve your organization’s cybersecurity posture based on threat actor activity and to reduce the risk of compromise by ALPHV Blackcat threat actors. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.
Secure remote access tools by:
Implementing application controls to manage and control execution of software, including allowlisting remote access programs. Application controls should prevent installation and execution of portable versions of unauthorized remote access and other software. A properly configured application allowlisting solution will block any unlisted application execution. Allowlisting is important because antivirus solutions may fail to detect the execution of malicious portable executables when the files use any combination of compression, encryption, or obfuscation.
Applying recommendations in CISA's joint Guide to Securing Remote Access Software.
Implementing FIDO/WebAuthn authentication or Public key Infrastructure (PKI)-based MFA [CPG 2.H]. These MFA implementations are resistant to phishing and not susceptible to push bombing or SIM swap attacks, which are techniques known be used by ALPHV Blackcat affiliates. See CISA’s Fact Sheet Implementing Phishing-Resistant MFA for more information.
Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting ransomware, implement a tool that logs and reports all network traffic [CPG 5.1], including lateral movement activity on a network. Endpoint detection and response (EDR) tools are useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
Implement user training on social engineering and phishing attacks [CPG 2.I]. Regularly educate users on identifying suspicious emails and links, not interacting with those suspicious items, and the importance of reporting instances of opening suspicious emails, links, attachments, or other potential lures.
Implement internal mail and messaging monitoring. Monitoring internal mail and messaging traffic to identify suspicious activity is essential as users may be phished from outside the targeted network or without the knowledge of the organizational security team. Establish a baseline of normal network traffic and scrutinize any deviations.
Implement free security tools to prevent cyber threat actors from redirecting users to malicious websites to steal their credentials. For more information see, CISA’s Free Cybersecurity Services and Tools webpage.
Install and maintain antivirus software. Antivirus software recognizes malware and protects your computer against it. Installing antivirus software from a reputable vendor is an important step in preventing and detecting infections. Always visit vendor sites directly rather than clicking on advertisements or email links. Because attackers are continually creating new viruses and other forms of malicious code, it is important to keep your antivirus software up to date.
VALIDATE SECURITY CONTROLS
In addition to applying mitigations, CISA recommends exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA recommends testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.
To get started:
Select an ATT&CK technique described in this advisory (see Tables 1-3).
Align your security technologies against the technique.
Test your technologies against the technique.
Analyze your detection and prevention technologies’ performance.
Repeat the process for all security technologies to obtain a set of comprehensive performance data.
Tune your security program, including people, processes, and technologies, based on the data generated by this process.
CISA and FBI recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.
RESOURCES
Stopransomware.gov is a whole-of-government approach that gives one central location for ransomware resources and alerts.
Resource to reduce the risk of a ransomware attack: #StopRansomware Guide.
No-cost cyber hygiene services: Cyber Hygiene Services and Ransomware Readiness Assessment.
DISCLAIMER
The information in this report is being provided “as is” for informational purposes only. CISA and FBI do not endorse any commercial entity, product, company, or service, including any entities, products, or services linked within this document. Any reference to specific commercial entities, products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by CISA and FBI.
VERSION HISTORY
December 19, 2023: Initial version.
Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.
The Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA) are releasing this joint CSA to disseminate known IOCs and TTPs associated with the ALPHV Blackcat ransomware as a service (RaaS) identified through FBI investigations as recently as Dec. 6, 2023.
This advisory provides updates to the FBI FLASH BlackCat/ALPHV Ransomware Indicators of Compromise released April 19, 2022. Since previous reporting, ALPHV Blackcat actors released a new version of the malware, and the FBI identified over 1000 victims worldwide targeted via ransomware and/or data extortion.
FBI and CISA encourage critical infrastructure organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of ALPHV Blackcat ransomware and data extortion incidents.
In February 2023, ALPHV Blackcat administrators announced the ALPHV Blackcat Ransomware 2.0 Sphynx update, which was rewritten to provide additional features to affiliates, such as better defense evasion and additional tooling. This ALPHV Blackcat update has the capability to encrypt both Windows and Linux devices, and VMWare instances. ALPHV Blackcat affiliates have extensive networks and experience with ransomware and data extortion operations. According to the FBI, as of September 2023, ALPHV Blackcat affiliates have compromised over 1000 entities—nearly 75 percent of which are in the United States and approximately 250 outside the United States—, demanded over $500 million, and received nearly $300 million in ransom payments.
Download the PDF version of this report:
AA23-353A #StopRansomware: ALPHV Blackcat
(PDF, 477.69 KB
)
TECHNICAL DETAILS
Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 14. See the MITRE ATT&CK Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.
ALPHV Blackcat affiliates use advanced social engineering techniques and open source research on a company to gain initial access. Actors pose as company IT and/or helpdesk staff and use phone calls or SMS messages [T1598] to obtain credentials from employees to access the target network [T1586]. ALPHV Blackcat affiliates use uniform resource locators (URLs) to live-chat with victims to convey demands and initiate processes to restore the victims’ encrypted files.
After gaining access to a victim network, ALPHV Blackcat affiliates deploy remote access software such as AnyDesk, Mega sync, and Splashtop in preparation of data exfiltration. After gaining access to networks, ALPHV Blackcat affiliates use legitimate remote access and tunneling tools, such as Plink and Ngrok [S0508]. ALPHV Blackcat affiliates claim to use Brute Ratel C4 [S1063] and Cobalt Strike [S1054] as beacons to command and control servers. ALPHV Blackcat affiliates use the open source adversary-in-the-middle attack [T1557] framework Evilginx2, which allows them to obtain multifactor authentication (MFA) credentials, login credentials, and session cookies. The actors also obtain passwords from the domain controller, local network, and deleted backup servers to move laterally throughout the network [T1555].
To evade detection, affiliates employ allowlisted applications such as Metasploit. Once installed on the domain controller, the logs are cleared on the exchange server. Then Mega.nz or Dropbox are used to move, exfiltrate, and/or download victim data. The ransomware is then deployed, and the ransom note is embedded as a file.txt. According to public reporting, affiliates have additionally used POORTRY and STONESTOP to terminate security processes.
Some ALPHV Blackcat affiliates exfiltrate data after gaining access and extort victims without deploying ransomware. After exfiltrating and/or encrypting data, ALPHV Blackcat affiliates communicate with victims via TOR [S0183], Tox, email, or encrypted applications. The threat actors then delete victim data from the victim’s system.
ALPHV Blackcat affiliates offer to provide unsolicited cyber remediation advice as an incentive for payment, offering to provide victims with “vulnerability reports” and “security recommendations” detailing how they penetrated the system and how to prevent future re-victimization upon receipt of ransom payment.
MITRE ATT&CK TACTICS AND TECHNIQUES
See Table 1 through Table 3 for all referenced threat actor tactics and techniques in this advisory.
Table 1: ALPHV Blackcat/ALPHV Threat Actors ATT&CK Techniques - Reconnaissance
Technique Title
ID
Use
Phishing for Information
T1598
ALPHV Blackcat affiliates pose as company IT and/or helpdesk staff using phone calls or SMS messages to obtain credentials from employees to access the target network.
Table 2: ALPHV Blackcat/ALPHV Threat Actors ATT&CK Techniques – Resource Development
Technique Title
ID
Use
Compromise Accounts
T1586
ALPHV Blackcat affiliates use compromised accounts to gain access to victims’ networks.
Table 3: ALPHV Blackcat/ALPHV Threat Actors ATT&CK Techniques – Credential Access
Technique Title
ID
Use
Obtain Credentials from Passwords Stores
T1555
ALPHV Blackcat affiliates obtain passwords from local networks, deleted servers, and domain controllers.
Adversary-in-the-Middle
T1557
ALPHV Blackcat/ALPHV affiliates use the open-source framework Evilginx2 to obtain MFA credentials, login credentials, and session cookies for targeted networks.
INCIDENT RESPONSE
If compromise is detected, organizations should:
Quarantine or take offline potentially affected hosts.
Reimage compromised hosts.
Provision new account credentials.
Collect and review artifacts such as running processes/services, unusual authentications, and recent network connections.
Report the compromise or phishing incident to CISA via CISA’s 24/7 Operations Center (report@cisa.gov or 888-282-0870). State, local, tribal, or territorial government entities can also report to MS-ISAC (SOC@cisecurity.org or 866-787-4722).
To report spoofing or phishing attempts (or to report that you’ve been a victim), file a complaint with the FBI’s Internet Crime Complaint Center (IC3), or contact your local FBI Field Office to report an incident.
MITIGATIONS
These mitigations apply to all critical infrastructure organizations and network defenders. The FBI and CISA recommend that software manufactures incorporate secure-by-design and -default principles and tactics into their software development practices limiting the impact of ransomware techniques, thus, strengthening the security posture for their customers.
For more information on secure by design, see CISA’s Secure by Design webpage and joint guide.
FBI and CISA recommend organizations implement the mitigations below to improve your organization’s cybersecurity posture based on threat actor activity and to reduce the risk of compromise by ALPHV Blackcat threat actors. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.
Secure remote access tools by:
Implementing application controls to manage and control execution of software, including allowlisting remote access programs. Application controls should prevent installation and execution of portable versions of unauthorized remote access and other software. A properly configured application allowlisting solution will block any unlisted application execution. Allowlisting is important because antivirus solutions may fail to detect the execution of malicious portable executables when the files use any combination of compression, encryption, or obfuscation.
Applying recommendations in CISA's joint Guide to Securing Remote Access Software.
Implementing FIDO/WebAuthn authentication or Public key Infrastructure (PKI)-based MFA [CPG 2.H]. These MFA implementations are resistant to phishing and not susceptible to push bombing or SIM swap attacks, which are techniques known be used by ALPHV Blackcat affiliates. See CISA’s Fact Sheet Implementing Phishing-Resistant MFA for more information.
Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting ransomware, implement a tool that logs and reports all network traffic [CPG 5.1], including lateral movement activity on a network. Endpoint detection and response (EDR) tools are useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
Implement user training on social engineering and phishing attacks [CPG 2.I]. Regularly educate users on identifying suspicious emails and links, not interacting with those suspicious items, and the importance of reporting instances of opening suspicious emails, links, attachments, or other potential lures.
Implement internal mail and messaging monitoring. Monitoring internal mail and messaging traffic to identify suspicious activity is essential as users may be phished from outside the targeted network or without the knowledge of the organizational security team. Establish a baseline of normal network traffic and scrutinize any deviations.
Implement free security tools to prevent cyber threat actors from redirecting users to malicious websites to steal their credentials. For more information see, CISA’s Free Cybersecurity Services and Tools webpage.
Install and maintain antivirus software. Antivirus software recognizes malware and protects your computer against it. Installing antivirus software from a reputable vendor is an important step in preventing and detecting infections. Always visit vendor sites directly rather than clicking on advertisements or email links. Because attackers are continually creating new viruses and other forms of malicious code, it is important to keep your antivirus software up to date.
VALIDATE SECURITY CONTROLS
In addition to applying mitigations, CISA recommends exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA recommends testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.
To get started:
Select an ATT&CK technique described in this advisory (see Tables 1-3).
Align your security technologies against the technique.
Test your technologies against the technique.
Analyze your detection and prevention technologies’ performance.
Repeat the process for all security technologies to obtain a set of comprehensive performance data.
Tune your security program, including people, processes, and technologies, based on the data generated by this process.
CISA and FBI recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.
RESOURCES
Stopransomware.gov is a whole-of-government approach that gives one central location for ransomware resources and alerts.
Resource to reduce the risk of a ransomware attack: #StopRansomware Guide.
No-cost cyber hygiene services: Cyber Hygiene Services and Ransomware Readiness Assessment.
DISCLAIMER
The information in this report is being provided “as is” for informational purposes only. CISA and FBI do not endorse any commercial entity, product, company, or service, including any entities, products, or services linked within this document. Any reference to specific commercial entities, products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by CISA and FBI.
VERSION HISTORY
December 19, 2023: Initial version.
December 19, 2023
This is the second installment of the Azure Serial Console blog, which provides insights to improve defenders’ preparedness when investigating Azure Serial Console activity on Azure Linux virtual machines. While the first blog post discussed various tracing activities, such as using Azure activity and Sysmon logs on Windows virtual machines to trace serial console activity, this blog outlines how to enable logging for Azure Linux virtual machines using Sysmon for Linux to capture and how to send these events to a log analytics workspace.
December 18, 2023
Fortinet released security advisories to address multiple vulnerabilities in Fortinet products.
December 18, 2023
Microsoft released a security update to address multiple vulnerabilities in Microsoft Edge.
December 18, 2023
Affected country: Argentina
Glide: ST-2023-000256-ARG
On 16 December in the city of Bahía Blanca, south of the Province of Buenos Aires, gusts of over 140 kms per hour not only affected access to services such as electricity and water, but also had an impact on urban infrastructure and homes. As a result, the Club Bahiense del Norte building collapsed and 13 people lost their lives, including a 4-year-old girl, and more than 20 were injured. The damage to the infrastructure of homes has been considerable, mainly in neighborhoods far from the central area of the city, with roofs blown off, falling masonry and walls, among others. Hundreds of electric power poles and old trees have fallen as a result of the intense winds, making it difficult to restore electric power and therefore delaying access to water in many communities, as well as delaying early recovery tasks, generating difficulties in accessing the most exposed communities. On 18 December the Governor of the Province of Buenos Aires decreed a State of Emergency for 30 days for the entire territory of the Province, which was made official in the Official Gazette.(IFRC, 30 Dec 2023)
December 14, 2023
SUMMARY
In January 2023, the Cybersecurity and Infrastructure Security Agency (CISA) conducted a Risk and Vulnerability Assessment (RVA) at the request of a Healthcare and Public Health (HPH) sector organization to identify vulnerabilities and areas for improvement. An RVA is a two-week penetration test of an entire organization, with one week spent on external testing and one week spent assessing the internal network. As part of the RVA, the CISA assessment team conducted web application, phishing, penetration, database, and wireless assessments. The assessed organization was a large organization deploying on-premises software.
During the one-week external assessment, the assessment team did not identify any significant or exploitable conditions in externally available systems that may allow a malicious actor to easily obtain initial access to the organization’s network. Furthermore, the assessment team was unable to gain initial access to the assessed organization through phishing. However, during internal penetration testing, the team exploited misconfigurations, weak passwords, and other issues through multiple attack paths to compromise the organization’s domain.
In coordination with the assessed organization, CISA is releasing this Cybersecurity Advisory (CSA) detailing the RVA team’s activities and key findings to provide network defenders and software manufacturers recommendations for improving their organizations’ and customers’ cyber posture, which reduces the impact of follow-on activity after initial access. CISA encourages the HPH sector and other critical infrastructure organizations deploying on-premises software, as well as software manufacturers, to apply the recommendations in the Mitigations section of this CSA to harden networks against malicious activity and to reduce the likelihood of domain compromise.
Download the PDF version of this report:
AA23-349A Enhancing Cyber Resilience: Insights from the CISA Healthcare and Public Health Sector Risk and Vulnerability Assessment
(PDF, 744.23 KB
)
TECHNICAL DETAILS
Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 14. See the MITRE ATT&CK Tactics and Techniques section for tables of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques with corresponding mitigation and/or detection recommendations. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.
Introduction
CISA has authority to, upon request, provide analyses, expertise, and other technical assistance to critical infrastructure owners and operators and provide operational and timely technical assistance to federal and non-federal entities with respect to cybersecurity risks. See generally 6 U.S.C. §§ 652(c)(5), 659(c)(6). After receiving a request for an RVA from the organization and coordinating high-level details of the engagement with certain personnel at the organization, CISA conducted the RVA in January 2023.
During RVAs, CISA tests the security posture of an organization’s network over a two-week period to determine the risk, vulnerability, and exploitability of systems and networks. During the first week (the external phase), the team tests public facing systems to identify exploitable vulnerabilities. During the second week (the internal phase), the team determines the susceptibility of the environment to an actor with internal access (e.g., malicious cyber actor or insider threat). The assessment team offers five services:
Web Application Assessment: The assessment team uses commercial and open source tools to identify vulnerabilities in public-facing and internal web applications, demonstrating how they could be exploited.
Phishing Assessment: The assessment team tests the susceptibility of staff and infrastructure to phishing attacks and determines what impact a phished user workstation could have on the internal network. The RVA team crafts compelling email pretexts and generates payloads, similar to ones used by threat actors, in order to provide a realistic threat perspective to the organization.
Penetration Testing: The assessment team tests the security of an environment by simulating scenarios an advanced cyber actor may attempt. The team’s goals are to establish a foothold, escalate privileges, and compromise the domain. The RVA team leverages both open source and commercial tools for host discovery, port and service mapping, vulnerability discovery and analysis, and vulnerability exploitation.
Database Assessment: The assessment team uses commercial database tools to review databases for misconfigurations and missing patches.
Wireless Assessment: The assessment team uses specialized wireless hardware to assess wireless access points, connected endpoints, and user awareness for vulnerabilities.
The assessed organization was in the HPH sector. See Table 1 for services in-scope for this RVA.
Table 1: In-Scope RVA Services
Phase
Scope
Services
External Assessment
Publicly available HPH-organization endpoints discovered during scanning
Penetration Testing
Phishing Assessment
Web Application Assessment
Internal Assessment
Internally available HPH-organization endpoints discovered during scanning
Database Assessment
Penetration Testing
Web Application Assessment
Wireless Assessment
Phase I: External Assessment
Penetration and Web Application Testing
The CISA team did not identify any significant or exploitable conditions from penetration or web application testing that may allow a malicious actor to easily obtain initial access to the organization’s network.
Phishing Assessment
The CISA team conducted phishing assessments that included both user and systems testing.
The team’s phishing assessment was unsuccessful because the organization’s defensive tools blocked the execution of the team’s payloads. The payload testing resulted in most of the team’s payloads being blocked by host-based protections through a combination of browser, policy, and antivirus software. Some of the payloads were successfully downloaded to disk without being immediately removed, but upon execution, the antivirus software detected the malicious code and blocked it from running. Some payloads appeared to successfully evade host-based protections but did not create a connection to the command and control (C2) infrastructure, indicating they may have been incompatible with the system or blocked by border protections.
Since none of the payloads successfully connected to the assessment team’s C2 server, the team conducted a credential harvesting phishing campaign. Users were prompted to follow a malicious link within a phishing email under the pretext of verifying tax information and were then taken to a fake login form.
While twelve unique users from the organization submitted credentials through the malicious form, the CISA team was unable to leverage the credentials because they had limited access to external-facing resources. Additionally, the organization had multi-factor authentication (MFA) implemented for cloud accounts. Note: At the time of the assessment, the CISA team’s operating procedures did not include certain machine-in-the-middle attacks that could have circumvented the form of MFA in place. However, it is important to note that tools like Evilginx[1] can be leveraged to bypass non-phishing resistant forms of MFA. Furthermore, if a user executes a malicious file, opening a connection to a malicious actor’s command and control server, MFA will not prevent the actor from executing commands and carrying out actions under the context of that user.
Phase II: Internal Assessment
Database, Web Application, and Wireless Testing
The CISA assessment team did not identify any significant or exploitable conditions from database or wireless testing that may allow a malicious actor to easily compromise the confidentiality, integrity, and availability of the tested environment.
The team did identify default credentials [T1078.001] for multiple web interfaces during web application testing and used default printer credentials while penetration testing. (See the Attack Path 2 section for more information.)
Penetration Testing
The assessment team starts internal penetration testing with a connection to the organization’s network but without a valid domain account. The team’s goal is to compromise the domain by gaining domain admin or enterprise administrator-level permissions. Generally, the team first attempts to gain domain user access and then escalate privileges until the domain is compromised. This process is called the “attack path”—acquiring initial access to an organization and escalating privileges until the domain is compromised and/or vital assets for the organization are accessed. The attack path requires specialized expertise and is realistic to what adversaries may do in an environment.
For this assessment, the team compromised the organization’s domain through four unique attack paths, and in a fifth attack path the team obtained access to sensitive information.
See the sections below for a description of the team’s attack paths mapped to the MITRE ATT&CK for Enterprise framework. See the Findings section for information on issues that enabled the team to compromise the domain.
Attack Path 1
The assessment team initiated LLMNR/NBT-NS/mDNS/DHCP poisoning [T1557.001] with Responder[2], which works in two steps:
Responder listens to multicast name resolution queries (e.g., LLMNR UDP/5355, NBTNS UDP/137) [T1040] and under the right conditions spoofs a response to direct the victim host to a CISA-controlled machine on which Responder is running.
Once a victim connects to the machine, Responder exploits the connection to perform malicious functions such as stealing credentials or opening a session on a targeted host [T1021].
With this tool, the CISA team captured fifty-five New Technology Local Area Network Manager version 2 (NTLMv2) hashes, including the NTLMv2 hash for a service account. Note: NTLMv2 and other variations of the hash protocol are used for clients to join a domain, authenticate between Active Directory forests, authenticate between earlier versions of Windows operating systems (OSs), and authenticate computers that are not normally a part of the domain.[3] Cracking these passwords may enable malicious actors to establish a foothold in the domain and move laterally or elevate their privileges if the hash belongs to a privileged account.
The service account had a weak password, allowing the team to quickly crack it [T1110.002] and obtain access to the organization’s domain. With domain access, the CISA assessment team enumerated accounts with a Service Principal Name (SPN) set [T1087.002]. SPN is the unique service identifier used by Kerberos authentication[4], and accounts with SPN are susceptible to Kerberoasting.
The CISA team used Impacket’s[5] GetUserSPNs tool to request Ticket-Granting Service (TGS) tickets for all accounts with SPN set and obtained their Kerberos hashes [T1558.003]. Three of these accounts had domain administrator privileges—offline, the team cracked ACCOUNT 1 (which had a weak password).
Using CrackMapExec[6], the assessment team used ACCOUNT 1 [T1078.002] to successfully connect to a domain controller (DC). The team confirmed they compromised the domain because ACCOUNT 1 had READ,WRITE permissions over the C$ administrative share [T1021.002] (see Figure 1).
Figure 1: ACCOUNT 1 Domain Admin PrivilegesTo further demonstrate the impact of compromising ACCOUNT 1, the assessment team used it to access a virtual machine interface. If a malicious actor compromised ACCOUNT 1, they could use it to modify, power off [T1529], and/or delete critical virtual machines, including domain controllers and file servers.
Attack Path 2
The team first mapped the network to identify open web ports [T1595.001], and then attempted to access various web interfaces [T1133] with default administrator credentials. The CISA team was able to log into a printer interface with a default password and found the device was configured with domain credentials to allow employees to save scanned documents to a network share [T1080].
While logged into the printer interface as an administrator, the team 1) modified the “Save as file” configuration to use File Transfer Protocol (FTP) instead of Server Message Block (SMB) and 2) changed the Server Name and Network Path to point to a CISA-controlled machine running Responder [T1557]. Then, the team executed a “Connection Test” that sent the username and password over FTP [T1187] to the CISA machine running Responder, which captured cleartext credentials for a non-privileged domain account (ACCOUNT 2).
Using ACCOUNT 2 and Certipy[7], the team enumerated potential certificate template vulnerabilities found in Active Directory Certificate Services (ADCS). Note: ADCS templates are used to build certificates for different types of servers and other entities on an organization’s network. Malicious actors can exploit template misconfigurations [T1649] to manipulate the certificate infrastructure into issuing fraudulent certificates and/or escalate user privileges to a domain administrator.
The WebServer template was misconfigured to allow all authenticated users permission to:
Change the properties of the template (via Object Control Permissions with Write Property Principals set to Authenticated Users).
Enroll for the certificate (via Enrollment Permissions including the Authenticated Users group).
Request a certificate for a different user (via EnrolleeSuppliesSubject set as True).
See Figure 2 for the displayed certificate template misconfigurations.
The template’s Client Authentication was set to False, preventing the CISA assessment team from requesting a certificate that could be used to authenticate to a server in the domain. To demonstrate how this misconfiguration could lead to privilege escalation, the assessment team, leveraging its status as a mere authenticated user, briefly changed the WebServer template properties to set Client Authentication to True so that a certificate could be obtained for server authentication, ensuring the property was set back to its original setting of False immediately thereafter.
The team used Certipy with the ACCOUNT 2 credentials to request a certificate for a Domain Administrator account (ACCOUNT 3). The team then authenticated to the domain controller as ACCOUNT 3 with the generated certificate [T1550] and retrieved the NTLM hash for ACCOUNT 3 [T1003]. The team used the hash to authenticate to the domain controller [T1550.002] and validated Domain Administrator privileges, demonstrating compromise of the domain via the WebServer template misconfiguration.
Attack Path 3
The CISA team used a tool called CrackMapExec to spray easily guessable passwords [T1110.003] across all domain accounts and obtained two sets of valid credentials for standard domain user accounts.
The assessment team leveraged one of the domain user accounts (ACCOUNT 4) to enumerate ADCS via Certipy and found that web enrollment was enabled (see Figure 3). If web enrollment is enabled, malicious actors can abuse certain services and/or misconfigurations in the environment to coerce a server to authenticate to an actor-controlled computer, which can relay the authentication to the ADCS web enrollment service and obtain a certificate for the server’s account (known as a relay attack).
Figure 3: Misconfigured ADCS Enumerated via CertipyThe team used PetitPotam [8] with ACCOUNT 4 credentials to force the organization’s domain controller to authenticate to the CISA-operated machine and then used Certipy to relay the coerced authentication attempt to the ADCS web enrollment service to receive a valid certificate for ACCOUNT 5, the domain controller machine account. They used this certificate to acquire a TGT [T1558] for ACCOUNT 5.
With the TGT for ACCOUNT 5, the CISA team used DCSync to dump the NTLM hash [T1003.006] for ACCOUNT 3 (a Domain Administrator account [see Attack Path 2 section]), effectively leading to domain compromise.
Attack Path 4
The CISA team identified several systems on the organization’s network that do not enforce SMB signing. The team exploited this misconfiguration to obtain cleartext credentials for two domain administrator accounts.
First, the team used Responder to capture the NTLMv2 hash for a domain administrator account. Next, they used Impacket’s NTLMrelayx tool[9] to relay the authentication for the domain administrator, opening a SOCKS connection on a host that did not enforce SMB signing. The team then used DonPAPI[10] to dump cleartext credentials through the SOCKS connection and obtained credentials for two additional domain administrator accounts.
The CISA team validated the privileges of these accounts by checking for READ,WRITE access on a domain controller C$ share [T1039], demonstrating Domain Administrator access and therefore domain compromise.
Attack Path 5
The team did vulnerability scanning [T1046] and identified a server vulnerable to CVE-2017-0144 (an Improper Input Validation [CWE-20] vulnerability known as “EternalBlue” that affects SMB version 1 [SMBv1] and enables remote code execution [see Figure 4]).
Figure 4: Checking for EternalBlue VulnerabilityThe CISA assessment team then executed a well-known EternalBlue exploit [T1210] and established a shell on the server. This shell allowed them to execute commands [T1059.003] under the context of the local SYSTEM account.
With this local SYSTEM account, CISA dumped password hashes from a Security Account Manager (SAM) database [T1003.002]. The team parsed the hashes and identified one for a local administrator account. Upon parsing the contents of the SAM database dump, the CISA team identified an NTLM hash for the local administrator account, which can be used to authenticate to various services.
The team sprayed the acquired NTLM hash across a network segment and identified multiple instances of password reuse allowing the team to access various resources including sensitive information with the hash.
Findings
Key Issues
The CISA assessments team identified several findings as potentially exploitable vulnerabilities that could compromise the confidentiality, integrity, and availability of the tested environment. Each finding, listed below, includes a description with supporting details. See the Mitigations section for recommendations on how to mitigate these issues.
The CISA team rated their findings on a severity scale from critical to informational (see Table 2).
Table 2: Severity Rating Criteria
Severity
Description
Critical
Critical vulnerabilities pose an immediate and severe risk to the environment because of the ease of exploitation and potential impact. Critical items are reported to the customer immediately.
High
Malicious actors may be able to exercise full control on the targeted device.
Medium
Malicious actors may be able to exercise some control of the targeted device.
Low
The vulnerabilities discovered are reported as items of interest but are not normally exploitable. Many low items reported by security tools are not included in this report because they are often informational, unverified, or of minor risk.
Informational
These vulnerabilities are potential weaknesses within the system that cannot be readily exploited. These findings represent areas that the customer should be cognizant of, but do not require any immediate action.
The CISA assessment team identified four High severity vulnerabilities and one Medium severity vulnerability during penetration testing that contributed to the team’s ability to compromise the domain. See Table 3 for a list and description of these findings.
Table 3: Key Issues Contributing to Domain Compromise
Issue
Severity
Service
Description
Poor Credential Hygiene: Easily Crackable Passwords
High
Penetration Testing
As part of their assessment, the team reviewed the organization’s domain password policy and found it was weak because the minimum password length was set to 8 characters. Passwords less than 15 characters without randomness are easily crackable, and malicious actors with minimal technical knowledge can use these credentials to access the related services.
The assessment team was able to easily crack many passwords throughout the assessment to move laterally and increase access within the domain. Specifically, the team:
Cracked the NTLMv2 hash for a domain account, and subsequently accessed the domain. (See the Attack Path 1 section.)
Cracked the password hash (obtained via Kerberoasting) of a domain administrator account and subsequently compromised the domain. (See the Attack Path 1 section.)
Poor Credential Hygiene: Guessable Credentials
High
Penetration Testing
As part of the penetration test, the assessment team tested to see if one or more services is accessible using a list of enumerated usernames alongside an easily guessed password. The objective is to see if a malicious actor with minimal technical knowledge can use these credentials to access the related services, enabling them to move laterally or escalate privileges. Easily guessable passwords are often comprised of common words, seasons, months and/or years, and are sometimes combined with special characters. Additionally, phrases or names that are popular locally (such as the organization being tested or a local sports teams) may also be considered easily guessable.
The team sprayed common passwords against domain user accounts and obtained valid credentials for standard domain users. (See the Attack Path 3 section.) (Cracking was not necessary for this attack.)
Misconfigured ADCS Certificate Templates
High
Penetration Testing
The team identified a WebServer template configured to allow all authenticated users permission to change the properties of the template and obtain certificates for different users. The team exploited the template to acquire a certificate for a Domain Administrator account (see the Attack Path 2 section).
Unnecessary Network Services Enabled
High
Penetration Testing
Malicious actors can exploit security vulnerabilities and misconfigurations in network services, especially legacy services.
The assessment team identified legacy name resolution protocols (e.g., NetBIOS, LLMNR, mDNS) enabled in the network, and abused LLMNR to capture NTLMv2 hashes, which they then cracked and used for domain access. (See the Attack Path 1 section.)
The team also identified an ADCS server with web enrollment enabled and leveraged it to compromise the domain through coercion and relaying. (See Attack Path 3 section.)
Additionally, the team identified hosts with WebClient and Spooler services, which are often abused by malicious actors to coerce authentication.
Elevated Service Account Privileges
High
Penetration Testing
Applications often require user accounts to operate. These user accounts, which are known as service accounts, often require elevated privileges. If an application or service running with a service account is compromised, an actor may have the same privileges and access as the service account.
The CISA team identified a service account with Domain Administrator privileges and used it to access the domain after cracking its password (See the Attack Path 1 section).
SMB Signing Not Enabled
High
Penetration Testing
The CISA team identified several systems on the organization’s network that do not enforce SMB signing and exploited this for relayed authentication to obtain cleartext credentials for two domain administrator accounts.
Insecure Default Configuration: Default Credentials
Medium
Web Application Assessment
Many off-the-shelf applications are released with built-in administrative accounts using predefined credentials that can often be found with a simple web search. Malicious actors with minimal technical knowledge can use these credentials to access the related services.
During testing, the CISA team identified multiple web interfaces with default administrator credentials and used default credentials for a printer interface to capture domain credentials of a non-privileged domain account. (See the Attack Path 2 section.)
In addition to the issues listed above, the team identified three High and seven Medium severity findings. These vulnerabilities and misconfigurations may allow a malicious actor to compromise the confidentiality, integrity, and availability of the tested environment. See Table 4 for a list and description of these findings.
Table 4: Additional Key Issues
Issue
Severity
Service
Description
Poor Credential Hygiene: Password Reuse for Administrator and User Accounts
High
Penetration Testing
Elevated password reuse is when an administrator uses the same password for their user and administrator accounts. If the user account password is compromised, it can be used to gain access to the administrative account.
The assessment team identified an instance where the same password was set for an admin user’s administrative account as well as their standard user account.
Poor Credential Hygiene: Password Reuse for Administrator Accounts
Medium
Penetration Testing
If administrator passwords are the same for various administrator accounts, malicious actors can use the password to access all systems that share this credential after compromising one account.
The assessment team found multiple instances of local administrator accounts across various systems using the same password.
Poor Patch Management: Out-of-Date Software
High
Penetration Testing
Patches and updates are released to address existing and emerging security vulnerabilities, and failure to apply the latest leaves systems open to attack with publicly available exploits. (The risk presented by missing patches and updates depends on the severity of the vulnerability).
The assessment team identified several unpatched systems including instances of CVE-2019-0708 (known as “BlueKeep”) and EternalBlue.
The team was unable to successfully compromise the systems with BlueKeep, but they did exploit EternalBlue on a server to implant a shell on a server with local SYSTEM privileges (see the Attack Path 5 section).
Poor Patch Management: Unsupported OS or Application
High
Penetration Testing
Using software or hardware that is no longer supported by the vendor poses a significant security risk because new and existing vulnerabilities are no longer patched). There is no way to address security vulnerabilities on these devices to ensure that they are secure. The overall security posture of the entire network is at risk because an attacker can target these devices to establish an initial foothold into the network.
The assessment team identified end-of-life (EOL) Windows Server 2008 R2 and Windows Server 2008 and Windows 5.1.
Use of Weak Authentication Measures
Medium
Penetration Testing
Applications may have weak or broken mechanisms to verify user identity before granting user access to protected functionalities. Malicious actors can exploit these to bypass authentication and gain access to use application resources and functionality.
The assessment team abused the Cisco Smart Install protocol to obtain configuration files for several Cisco devices on the organization’s network. These files contained encrypted Cisco passwords. (The CISA team was unable to crack these passwords within the assessment timeframe.)
PII Disclosure
Medium
Penetration Testing
The assessment team identified an unencrypted Excel file containing PII on a file share.
Hosts with Unconstrained Delegation Enabled Unnecessarily
Medium
Penetration Testing
The CISA team identified two systems that appeared to be configured with Unconstrained Delegation enabled. Hosts with Unconstrained Delegation enabled store the Kerberos TGTs of all users that authenticate to that host, enabling actors to steal service tickets or compromise krbtgt accounts and perform golden ticket or silver ticket attacks.
Although the assessment team was unable to fully exploit this configuration because they lost access to one of the vulnerable hosts, it could have led to domain compromise under the right circumstances.
Cleartext Password Disclosure
Medium
Penetration Testing
Storing passwords in cleartext is a security risk because malicious actors with access to these files can use them.
The assessment team identified several unencrypted files on a file share containing passwords for various personal and organizational accounts.
Insecure File Shares
Medium
Penetration Testing
Access to sensitive data (e.g., data related to business functions, IT functions, and/or personnel) should be restricted to only certain authenticated and authorized users.
The assessment team found an unsecured directory on a file share with sensitive IT information. The directory was accessible to all users in the domain group. Malicious actors with user privileges could access and/or exfiltrate this data.
Additional Issues
The CISA team identified one Informational severity within the organization’s networks and systems. These issues may allow a malicious actor to compromise the confidentiality, integrity, and availability of the tested environment, but are not readily exploitable. The information provided is to encourage the stakeholder to investigate these issues further to adjust their environments or eliminate certain aspects as needed, but the urgency is low.
Table 5: Informational Issues That CISA Team Noted
Issue
Severity
Service
Description
Overly Permissive Accounts
Informational
Penetration Testing
Account privileges are intended to control user access to host or application resources to limit access to sensitive information in support of a least-privilege security model. When user (or other) accounts have high privileges, users can see and/or do things they normally should not, and malicious actors can exploit this to access host and application resources.
The assessment team identified Active Directory objects where the Human Resources group appeared to be part of the privileged Account Operators group. This may have provided elevated privileges to accounts in the Human Resources group. (The CISA team was unable to validate and demonstrate the potential impact of this relationship within the assessment period).
Noted Strengths
The CISA team noted the following business, technical, and administrative components that enhanced the network security posture of the tested environment:
The organization’s network was found to have several strong, security-oriented characteristics such as:
Effective antivirus software;
Endpoint detection and response capabilities;
Good policies and best practices for protecting users from malicious files including not allowing users to mount ISO files;
Minimal external attack surface, limiting an adversary’s ability to leverage external vulnerabilities to gain initial access to the organization’s networks and systems;
Strong wireless protocols;
And network segmentation.
The organization’s security also demonstrated their ability to detect some of the CISA team's actions throughout testing and overall situational awareness through the use of logs and alerts.
The organization used MFA for cloud accounts. The assessment team obtained cloud credentials via a phishing campaign but was unable to use them because of MFA prompts.
MITIGATIONS
Network Defenders
CISA recommends HPH Sector and other critical infrastructure organizations implement the mitigations in Table 6 to mitigate the issues listed in the Findings section of this advisory. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.
Table 6: Recommendations to Mitigate Identified Issues
Issue
Recommendation
Poor Credential Hygiene: Easily Crackable Passwords
Follow National Institute of Standards and Technologies (NIST) guidelines when creating password policies to enforce use of “strong” passwords that cannot be cracked [CPG 2.B].[11] Consider using password managers to generate and store passwords.
Use “strong” passphrases for private keys to make cracking resource intensive [CPG 2.B]. Do not store credentials within the registry in Windows systems. Establish an organizational policy that prohibits password storage in files.
Ensure adequate password length (ideally 15+ characters) and complexity requirements for Windows service accounts and implement passwords with periodic expiration on these accounts [CPG 2.B]. Use Managed Service Accounts, when possible, to manage service account passwords automatically.
Poor Credential Hygiene: Guessable Credentials
Do not reuse local administrator account passwords across systems. Ensure that passwords are “strong” and unique [CPG 2.C].
Use phishing-resistant multi-factor authentication (MFA) for all administrative access, including domain administrative access [CPG 2.H]. If an organization that uses mobile push-notification-based MFA is unable to implement phishing-resistant MFA, use number matching to mitigate MFA fatigue. For more information, see CISA fact sheets on Implementing Phishing-Resistant MFA and Implementing Number Matching in MFA Applications.
Misconfigured ADCS Certificate Templates
Restrict enrollment rights in templates to only those users or groups that require it. Remove the Enrollee Supplies Subject flag from templates if it is not necessary or enforce manager approval if required. Consider removing Write Owner, Write DACL and Write Property permissions from low-privilege groups, such as Authenticated Users where those permissions are not needed.
Unnecessary Network Services Enabled
Ensure that only ports, protocols, and services with validated business needs are running on each system. Disable deprecated protocols (including NetBIOS, LLMNR, and mDNS) on the network that are not strictly necessary for business functions, or limit the systems and services that use the protocol, where possible [CPG 2.W].
Disable the WebClient and Spooler services where possible to minimize risk of coerced authentication.
Disable ADCS web-enrollment services. If this service cannot be disabled, disable NTLM authentication to prevent malicious actors from performing NTLM relay attacks or abusing the Spooler and WebClient services to coerce and relay authentication to the web-enrollment service.
Elevated Service Account Privileges
Run daemon applications using a non-Administrator account when appropriate.
Configure Service accounts with only the permissions necessary for the services they operate.
To mitigate Kerberoasting attacks, use AES or stronger encryption instead of RC4 for Kerberos hashes [CPG 2.K]. RC4 is considered weak encryption.
SMB Signing Not Enabled
Require SMB signing for both SMB client and server on all systems to prevent certain adversary-in-the-middle and pass-the-hash attacks. See Microsoft’s Overview of Server Message Block signing for more information.
Insecure Default Configuration: Default Credentials
Verify the implementation of appropriate hardening measures, and change, remove, or deactivate all default credentials [CPG 2.A].
Before deploying any new devices in a networked environment, change all default passwords for applications, operating systems, routers, firewalls, wireless access points, and other systems to have values consistent with administration-level accounts [CPG 2.A].
Poor Credential Hygiene: Password Reuse for Administrator and User Accounts
Discontinue reuse or sharing of administrative credentials among user/administrative accounts [CPG 2.C].
Use unique credentials across workstations, when possible, in accordance with applicable federal standards, industry best practices, and/or agency-defined requirements.
Train users, especially privileged users, against password reuse [CPG 2.I].
Poor Credential Hygiene: Password Reuse for Administrator Accounts
Discontinue reuse or sharing of administrative credentials among systems [CPG 2.C]. When possible, use unique credentials across all workstations in accordance with applicable federal standards, industry best practices, and/or agency-defined requirements.
Implement a security awareness program that focuses on the methods commonly used in intrusions that can be blocked through individual action [CPG 2.I].
Implement Local Administrator Password Solution (LAPS) where possible if your OS is older than Windows Server 2019 and Windows 10 as these versions do not have LAPS built in. Note: The authoring organizations recommend organizations upgrade to Windows Server 2019 and Windows 10 or greater.
Poor Patch Management: Out-of-Date Software
Enforce consistent patch management across all systems and hosts within the network environment [CPG 1.E].
Where patching is not possible due to limitations, implement network segregation controls [CPG 2.F] to limit exposure of the vulnerable system or host.
Consider deploying automated patch management tools and software update tools for operating system and software/applications on all systems for which such tools are available and safe.
Poor Patch Management: Unsupported OS or Application
Evaluate the use of unsupported hardware and software and discontinue where possible. If discontinuing the use of unsupported hardware and software is not possible, implement additional network protections to mitigate the risk.
Use of Weak Authentication Measures
Require phishing-resistant MFA for all user accounts that have access to sensitive data or systems. If MFA is not possible, it is recommended to, at a minimum, configure a more secure password policy by aligning with guidelines put forth by trusted entities such as NIST [CPG 2.H].
PII Disclosure
Implement a process to review files and systems for insecure handling of PII [CPG 2.L]. Properly secure or remove the information. Conduct periodic scans of server machines using automated tools to determine whether sensitive data (e.g., personally identifiable information, health, credit card, or classified information) is present on the system in cleartext.
Encrypt PII and other sensitive data, and train users who handle sensitive data to utilize best practices for encrypting data and storing it securely. If sensitive data must be stored on shares or other locations, restrict access to these locations as much as possible through access controls and network segmentation [CPG 2.F, 2.K, 2.L].
Hosts with Unconstrained Delegation Enabled Unnecessarily
Remove Unconstrained Delegation from all servers. If Unconstrained Delegation functionality is required, upgrade operating systems and applications to leverage other approaches (e.g., configure Constrained Delegation, enable the Account is sensitive and cannot be delegated option) or explore whether systems can be retired or further isolated from the enterprise. CISA recommends Windows Server 2019 or greater.
Cleartext Password Disclosure
Implement a review process for files and systems to look for cleartext account credentials. When credentials are found, remove or change them to maintain security [CPG 2.L].
Conduct periodic scans of server machines using automated tools to determine whether sensitive data (e.g., personally identifiable information, health, credit card, or classified information) is present on the system in cleartext. Consider implementing a secure password manager solution in cases where passwords need to be stored [CPG 2.L].
Insecure File Shares
Restrict access to file shares containing sensitive data to only certain authenticated and authorized users [CPG 2.L].
Additionally, CISA recommends that HPH sector organizations implement the following strategies to mitigate cyber threats:
Mitigation Strategy #1 Asset Management and Security:
CISA recommends that HPH sector organizations implement and maintain an asset management policy to reduce the risk of exposing vulnerabilities, devices, or services that could be exploited by threat actors to gain unauthorized access, steal sensitive data, or disrupt critical services. The focus areas for this mitigation strategy include asset management and asset security, addressing asset inventory, procurement, decommissioning, and network segmentation as they relate to hardware, software, and data assets.
Mitigation Strategy #2 Identity Management and Device Security:
CISA recommends entities secure their devices and digital accounts and manage their online access to protect sensitive data and PII/PHI from compromise. The focus areas for this mitigation strategy include email security, phising prevention, access management, password policies, data protection and loss prevention, and device logs and monitoring solutions.
Mitigation Strategy #3 Vulnerability, Patch, and Configuration Management:
CISA recommends entities mitigate known vulnerabilities and establish secure configuration baselines to reduce the likelihood of threat actors exploiting known vulnerabilities to breach organizational networks. The focus areas for this mitigation strategy include vulnerability and patch Management, and configuration and change management.
For more information on these mitigations strategies, see CISA’s Healthcare and Public Health Sector webpage.
Software Manufacturers
The above mitigations apply to HPH sector and other critical infrastructure organizations with on-premises or hybrid environments. Recognizing that insecure software is the root cause of the majority of these flaws, and that the responsibility should not be on the end user, CISA urges software manufacturers to implement the following to reduce the prevalence of misconfigurations, weak passwords, and other weaknesses identified and exploited through the assessment team:
Embed security into product architecture throughout the entire software development lifecycle (SDLC).
Eliminate default passwords. Do not provide software with default passwords. To eliminate default passwords, require administrators set a “strong” password [CPG 2.B] during installation and configuration.
Create secure configuration templates. Provide configuration templates with certain safe settings based on an organization’s risk appetite (e.g., low, medium, and high security templates). Support these templates with hardening guides based on the risks the manufacturer has identified. The default configuration should be a secure one, and organizations should need to opt in if they desire a less secure configuration.
Design products so that the compromise of a single security control does not result in compromise of the entire system. For example, narrowly provision user privileges by default and employ ACLs to reduce the impact of a compromised account. This will make it more difficult for a malicious cyber actor to escalate privileges and move laterally.
Mandate MFA, ideally phishing-resistant MFA, for privileged users and make MFA a default, rather than opt-in, feature.
These mitigations align with tactics provided in the joint guide Shifting the Balance of Cybersecurity Risk: Principles and Approaches for Secure by Design Software. CISA urges software manufacturers to take ownership of improving the security outcomes of their customers by applying these and other secure by design tactics. By using secure by design tactics, software manufacturers can make their product lines secure “out of the box” without requiring customers to spend additional resources making configuration changes, purchasing security software and logs, monitoring, and making routine updates.
For more information on secure by design, see CISA’s Secure by Design webpage. For more information on common misconfigurations and guidance on reducing their prevalence, see the joint advisory NSA and CISA Red and Blue Teams Share Top Ten Cybersecurity Misconfigurations.
VALIDATE SECURITY CONTROLS
In addition to applying the listed mitigations, CISA recommends exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA recommends testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.
To get started:
Select an ATT&CK technique described in this advisory (see Tables 7 – 16).
Align your security technologies against the technique.
Test your technologies against the technique.
Analyze your detection and prevention technologies’ performance.
Repeat the process for all security technologies to obtain a set of comprehensive performance data.
Tune your security program, including people, processes, and technologies, based on the data generated by this process.
CISA recommends continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.
RESOURCES
For consolidated findings from the RVAs by Fiscal Year mapped to MITRE ATT&CK, see CISA’s Risk and Vulnerability Assessments page.
See joint CSA NSA and CISA Red and Blue Teams Share Top Ten Cybersecurity Misconfigurations for information on the most common cybersecurity misconfigurations in large organizations and TTPs actors use to exploit these misconfigurations.
See CISA’s Healthcare and Public Health Sector webpage.
See CISA’s RedEye tool on CISA’s GitHub page. RedEye is an interactive open-source analytic tool used to visualize and report red team command and control activities. See CISA’s RedEye tool overview video for more information.
REFERENCES
[1] Github | kgretzky / evilginx
[2] Github | lgandx / Responder
[3] Network security LAN Manager authentication level - Windows Security | Microsoft Learn
[4] Service principal names - Win32 apps | Microsoft Learn
[5] Github | fortra / impacket
6] Github | byt3bl33d3r / CrackMapExec
[7] Github | ly4k / Certipy
[8] Github | topotam / PetitPotam
[9] Github | fortra / impacket / examples
[10] Github | login-securite / DonPAPI
[11] SP 800-63B, Digital Identity Guidelines: Authentication and Lifecycle Management | CSRC (nist.gov)
APPENDIX: MITRE ATT&CK TACTICS AND TECHNIQUES
Table 7: CISA Team ATT&CK Techniques for Reconnaissance
Reconnaissance
Technique Title
ID
Use
Active Scanning: Scanning IP Blocks
T1595.001
The CISA team first mapped the network to identify open web ports.
Table 8: CISA Team ATT&CK Techniques for Initial Access
Initial Access
Technique Title
ID
Use
Valid Accounts: Default Accounts
T1078.001
The CISA team did identify default credentials for multiple web interfaces during web application testing and used default printer credentials while penetration testing.
External Remote Services
T1133
The CISA team attempted to access various web interfaces with default administrator credentials.
Table 9: CISA Team ATT&CK Techniques for Execution
Execution
Technique Title
ID
Use
Command-Line Interface
T1059
The CISA team accessed a virtual machine interface enabling them to modify, power off, and/or delete critical virtual machines including domain controllers, file servers, and servers.
Command and Scripting Interpreter: Windows Command Shell
T1059.003
The CISA team used a webshell that allowed them to execute commands under the context of the local SYSTEM account.
Table 10: CISA Team ATT&CK Techniques for Privilege Escalation
Privilege Escalation
Technique Title
ID
Use
Valid Accounts: Domain Accounts
T1078.002
The CISA team used CrackMapExec to use ACCOUNT 1 to successfully connect to a domain controller (DC).
Table 11: CISA Team ATT&CK Techniques for Defense Evasion
Defense Evasion
Technique Title
ID
Use
Use Alternate Authentication Material
T1550
The CISA team authenticated to the domain controller as ACCOUNT 3 with the generated certificate.
Table 12: CISA Team ATT&CK Techniques for Credential Access
Credential Access
Technique Title
ID
Use
LLMNR/NBT-NS Poisoning and Relay
T1557.001
The CISA team initiated a LLMNR/NBT-NS/mDNS/DHCP poisoning tool to spoof a connection to the organization’s server for forced access.
Brute Force: Password Cracking
T1110.002
The CISA team cracked a service account with a weak password, giving them access to it.
Steal or Forge Kerberos Tickets: Kerberoasting
T1558.003
The CISA team gained access to domain accounts because any domain user can request a TGS ticket for domain accounts.
Adversary-in-the-Middle
T1557
The CISA team modified the “Save as file” configuration, to use File Transfer Protocol (FTP) instead of Server Message Block (SMB) and changed the Server Name and Network Path to point to a CISA-controlled machine running Responder.
Forced Authentication
T1187
The CISA team executed a “Connection Test” that sent the username and password over FTP.
Steal or Forge Authentication Certificates
T1649
The CISA team used Certipy to enumerate the ADCS certificate template vulnerabilities, allowing them to obtain certificates for different users.
OS Credential Dumping
T1003
The CISA team retrieved the NTLM hash for ACCOUNT 3.
Use Alternate Authentication Material: Pass the Hash
T1550.002
The CISA team used the hash to authenticate to the domain controller and validated Domain Administrator privileges, demonstrating compromise of the domain.
Brute Force: Password Spraying
T1110.003
The CISA team used a tool called CrackMapExec to spray easily guessable passwords across all domain accounts, giving them two sets of valid credentials.
Steal or Forge Kerberos Tickets
T1558
The CISA team used this certificate to acquire a TGT for ACCOUNT 5.
OS Credential Dumping: DCSync
T1003.006
The CISA team used DCSync to dump the NTLM hash for ACCOUNT 3 (a Domain Administrator account), effectively leading to domain compromise.
OS Credential Dumping: Security Account Manager
T1003.002
The CISA team dumped password hashes from a Security Account Manager (SAM) database.
Table 13: CISA Team ATT&CK Techniques for Discovery
Discovery
Technique Title
ID
Use
Network Sniffing
T1040
The CISA team spoofed a response to direct the victim host to a CISA-controlled machine on which Responder is running.
Account Discovery: Domain Account
T1087.002
The CISA team enumerated accounts with a Service Principal Name (SPN) set with their domain access.
Network Service Scanning
T1046
The CISA team canned the organization’s network to identify open web ports to see where they could leverage the default credentials they had.
Table 14: CISA Team ATT&CK Techniques for Lateral Movement
Lateral Movement
Technique Title
ID
Use
Remote Services
T1021
The CISA team exploited its Responder to perform malicious functions, such as stealing credentials or opening a session on a targeted host.
SMB/Windows Admin Shares
T1021.002
The CISA team confirmed they compromised the domain because ACCOUNT 1 had READ,WRITE permissions over the C$ administrative share.
Taint Shared Content
T1080
The CISA team found the device was configured with domain credentials to allow employees to save scanned documents to a network share.
Exploitation of Remote Services
T1210
The CISA team then executed a well-known EternalBlue exploit and established a shell on the server.
Table 15: CISA Team ATT&CK Techniques for Collection
Collection
Technique Title
ID
Use
Data from Network Shared Drive
T1039
The CISA team obtained credentials for cleartext, hashes, and from files.
Table 16: CISA Team ATT&CK Techniques for Impact
Collection
Technique Title
ID
Use
System Shutdown/Reboot
T1529
The CISA team assessed that with ACCOUNT 1, they could use it to modify, power off, and/or delete critical virtual machines, including domain controllers and file servers.
VERSION HISTORY
December 14, 2023: Initial version.
In January 2023, the Cybersecurity and Infrastructure Security Agency (CISA) conducted a Risk and Vulnerability Assessment (RVA) at the request of a Healthcare and Public Health (HPH) sector organization to identify vulnerabilities and areas for improvement. An RVA is a two-week penetration test of an entire organization, with one week spent on external testing and one week spent assessing the internal network. As part of the RVA, the CISA assessment team conducted web application, phishing, penetration, database, and wireless assessments. The assessed organization was a large organization deploying on-premises software.
During the one-week external assessment, the assessment team did not identify any significant or exploitable conditions in externally available systems that may allow a malicious actor to easily obtain initial access to the organization’s network. Furthermore, the assessment team was unable to gain initial access to the assessed organization through phishing. However, during internal penetration testing, the team exploited misconfigurations, weak passwords, and other issues through multiple attack paths to compromise the organization’s domain.
In coordination with the assessed organization, CISA is releasing this Cybersecurity Advisory (CSA) detailing the RVA team’s activities and key findings to provide network defenders and software manufacturers recommendations for improving their organizations’ and customers’ cyber posture, which reduces the impact of follow-on activity after initial access. CISA encourages the HPH sector and other critical infrastructure organizations deploying on-premises software, as well as software manufacturers, to apply the recommendations in the Mitigations section of this CSA to harden networks against malicious activity and to reduce the likelihood of domain compromise.
Download the PDF version of this report:
AA23-349A Enhancing Cyber Resilience: Insights from the CISA Healthcare and Public Health Sector Risk and Vulnerability Assessment
(PDF, 744.23 KB
)
TECHNICAL DETAILS
Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 14. See the MITRE ATT&CK Tactics and Techniques section for tables of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques with corresponding mitigation and/or detection recommendations. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.
Introduction
CISA has authority to, upon request, provide analyses, expertise, and other technical assistance to critical infrastructure owners and operators and provide operational and timely technical assistance to federal and non-federal entities with respect to cybersecurity risks. See generally 6 U.S.C. §§ 652(c)(5), 659(c)(6). After receiving a request for an RVA from the organization and coordinating high-level details of the engagement with certain personnel at the organization, CISA conducted the RVA in January 2023.
During RVAs, CISA tests the security posture of an organization’s network over a two-week period to determine the risk, vulnerability, and exploitability of systems and networks. During the first week (the external phase), the team tests public facing systems to identify exploitable vulnerabilities. During the second week (the internal phase), the team determines the susceptibility of the environment to an actor with internal access (e.g., malicious cyber actor or insider threat). The assessment team offers five services:
Web Application Assessment: The assessment team uses commercial and open source tools to identify vulnerabilities in public-facing and internal web applications, demonstrating how they could be exploited.
Phishing Assessment: The assessment team tests the susceptibility of staff and infrastructure to phishing attacks and determines what impact a phished user workstation could have on the internal network. The RVA team crafts compelling email pretexts and generates payloads, similar to ones used by threat actors, in order to provide a realistic threat perspective to the organization.
Penetration Testing: The assessment team tests the security of an environment by simulating scenarios an advanced cyber actor may attempt. The team’s goals are to establish a foothold, escalate privileges, and compromise the domain. The RVA team leverages both open source and commercial tools for host discovery, port and service mapping, vulnerability discovery and analysis, and vulnerability exploitation.
Database Assessment: The assessment team uses commercial database tools to review databases for misconfigurations and missing patches.
Wireless Assessment: The assessment team uses specialized wireless hardware to assess wireless access points, connected endpoints, and user awareness for vulnerabilities.
The assessed organization was in the HPH sector. See Table 1 for services in-scope for this RVA.
Table 1: In-Scope RVA Services
Phase
Scope
Services
External Assessment
Publicly available HPH-organization endpoints discovered during scanning
Penetration Testing
Phishing Assessment
Web Application Assessment
Internal Assessment
Internally available HPH-organization endpoints discovered during scanning
Database Assessment
Penetration Testing
Web Application Assessment
Wireless Assessment
Phase I: External Assessment
Penetration and Web Application Testing
The CISA team did not identify any significant or exploitable conditions from penetration or web application testing that may allow a malicious actor to easily obtain initial access to the organization’s network.
Phishing Assessment
The CISA team conducted phishing assessments that included both user and systems testing.
The team’s phishing assessment was unsuccessful because the organization’s defensive tools blocked the execution of the team’s payloads. The payload testing resulted in most of the team’s payloads being blocked by host-based protections through a combination of browser, policy, and antivirus software. Some of the payloads were successfully downloaded to disk without being immediately removed, but upon execution, the antivirus software detected the malicious code and blocked it from running. Some payloads appeared to successfully evade host-based protections but did not create a connection to the command and control (C2) infrastructure, indicating they may have been incompatible with the system or blocked by border protections.
Since none of the payloads successfully connected to the assessment team’s C2 server, the team conducted a credential harvesting phishing campaign. Users were prompted to follow a malicious link within a phishing email under the pretext of verifying tax information and were then taken to a fake login form.
While twelve unique users from the organization submitted credentials through the malicious form, the CISA team was unable to leverage the credentials because they had limited access to external-facing resources. Additionally, the organization had multi-factor authentication (MFA) implemented for cloud accounts. Note: At the time of the assessment, the CISA team’s operating procedures did not include certain machine-in-the-middle attacks that could have circumvented the form of MFA in place. However, it is important to note that tools like Evilginx[1] can be leveraged to bypass non-phishing resistant forms of MFA. Furthermore, if a user executes a malicious file, opening a connection to a malicious actor’s command and control server, MFA will not prevent the actor from executing commands and carrying out actions under the context of that user.
Phase II: Internal Assessment
Database, Web Application, and Wireless Testing
The CISA assessment team did not identify any significant or exploitable conditions from database or wireless testing that may allow a malicious actor to easily compromise the confidentiality, integrity, and availability of the tested environment.
The team did identify default credentials [T1078.001] for multiple web interfaces during web application testing and used default printer credentials while penetration testing. (See the Attack Path 2 section for more information.)
Penetration Testing
The assessment team starts internal penetration testing with a connection to the organization’s network but without a valid domain account. The team’s goal is to compromise the domain by gaining domain admin or enterprise administrator-level permissions. Generally, the team first attempts to gain domain user access and then escalate privileges until the domain is compromised. This process is called the “attack path”—acquiring initial access to an organization and escalating privileges until the domain is compromised and/or vital assets for the organization are accessed. The attack path requires specialized expertise and is realistic to what adversaries may do in an environment.
For this assessment, the team compromised the organization’s domain through four unique attack paths, and in a fifth attack path the team obtained access to sensitive information.
See the sections below for a description of the team’s attack paths mapped to the MITRE ATT&CK for Enterprise framework. See the Findings section for information on issues that enabled the team to compromise the domain.
Attack Path 1
The assessment team initiated LLMNR/NBT-NS/mDNS/DHCP poisoning [T1557.001] with Responder[2], which works in two steps:
Responder listens to multicast name resolution queries (e.g., LLMNR UDP/5355, NBTNS UDP/137) [T1040] and under the right conditions spoofs a response to direct the victim host to a CISA-controlled machine on which Responder is running.
Once a victim connects to the machine, Responder exploits the connection to perform malicious functions such as stealing credentials or opening a session on a targeted host [T1021].
With this tool, the CISA team captured fifty-five New Technology Local Area Network Manager version 2 (NTLMv2) hashes, including the NTLMv2 hash for a service account. Note: NTLMv2 and other variations of the hash protocol are used for clients to join a domain, authenticate between Active Directory forests, authenticate between earlier versions of Windows operating systems (OSs), and authenticate computers that are not normally a part of the domain.[3] Cracking these passwords may enable malicious actors to establish a foothold in the domain and move laterally or elevate their privileges if the hash belongs to a privileged account.
The service account had a weak password, allowing the team to quickly crack it [T1110.002] and obtain access to the organization’s domain. With domain access, the CISA assessment team enumerated accounts with a Service Principal Name (SPN) set [T1087.002]. SPN is the unique service identifier used by Kerberos authentication[4], and accounts with SPN are susceptible to Kerberoasting.
The CISA team used Impacket’s[5] GetUserSPNs tool to request Ticket-Granting Service (TGS) tickets for all accounts with SPN set and obtained their Kerberos hashes [T1558.003]. Three of these accounts had domain administrator privileges—offline, the team cracked ACCOUNT 1 (which had a weak password).
Using CrackMapExec[6], the assessment team used ACCOUNT 1 [T1078.002] to successfully connect to a domain controller (DC). The team confirmed they compromised the domain because ACCOUNT 1 had READ,WRITE permissions over the C$ administrative share [T1021.002] (see Figure 1).
Figure 1: ACCOUNT 1 Domain Admin PrivilegesTo further demonstrate the impact of compromising ACCOUNT 1, the assessment team used it to access a virtual machine interface. If a malicious actor compromised ACCOUNT 1, they could use it to modify, power off [T1529], and/or delete critical virtual machines, including domain controllers and file servers.
Attack Path 2
The team first mapped the network to identify open web ports [T1595.001], and then attempted to access various web interfaces [T1133] with default administrator credentials. The CISA team was able to log into a printer interface with a default password and found the device was configured with domain credentials to allow employees to save scanned documents to a network share [T1080].
While logged into the printer interface as an administrator, the team 1) modified the “Save as file” configuration to use File Transfer Protocol (FTP) instead of Server Message Block (SMB) and 2) changed the Server Name and Network Path to point to a CISA-controlled machine running Responder [T1557]. Then, the team executed a “Connection Test” that sent the username and password over FTP [T1187] to the CISA machine running Responder, which captured cleartext credentials for a non-privileged domain account (ACCOUNT 2).
Using ACCOUNT 2 and Certipy[7], the team enumerated potential certificate template vulnerabilities found in Active Directory Certificate Services (ADCS). Note: ADCS templates are used to build certificates for different types of servers and other entities on an organization’s network. Malicious actors can exploit template misconfigurations [T1649] to manipulate the certificate infrastructure into issuing fraudulent certificates and/or escalate user privileges to a domain administrator.
The WebServer template was misconfigured to allow all authenticated users permission to:
Change the properties of the template (via Object Control Permissions with Write Property Principals set to Authenticated Users).
Enroll for the certificate (via Enrollment Permissions including the Authenticated Users group).
Request a certificate for a different user (via EnrolleeSuppliesSubject set as True).
See Figure 2 for the displayed certificate template misconfigurations.
The template’s Client Authentication was set to False, preventing the CISA assessment team from requesting a certificate that could be used to authenticate to a server in the domain. To demonstrate how this misconfiguration could lead to privilege escalation, the assessment team, leveraging its status as a mere authenticated user, briefly changed the WebServer template properties to set Client Authentication to True so that a certificate could be obtained for server authentication, ensuring the property was set back to its original setting of False immediately thereafter.
The team used Certipy with the ACCOUNT 2 credentials to request a certificate for a Domain Administrator account (ACCOUNT 3). The team then authenticated to the domain controller as ACCOUNT 3 with the generated certificate [T1550] and retrieved the NTLM hash for ACCOUNT 3 [T1003]. The team used the hash to authenticate to the domain controller [T1550.002] and validated Domain Administrator privileges, demonstrating compromise of the domain via the WebServer template misconfiguration.
Attack Path 3
The CISA team used a tool called CrackMapExec to spray easily guessable passwords [T1110.003] across all domain accounts and obtained two sets of valid credentials for standard domain user accounts.
The assessment team leveraged one of the domain user accounts (ACCOUNT 4) to enumerate ADCS via Certipy and found that web enrollment was enabled (see Figure 3). If web enrollment is enabled, malicious actors can abuse certain services and/or misconfigurations in the environment to coerce a server to authenticate to an actor-controlled computer, which can relay the authentication to the ADCS web enrollment service and obtain a certificate for the server’s account (known as a relay attack).
Figure 3: Misconfigured ADCS Enumerated via CertipyThe team used PetitPotam [8] with ACCOUNT 4 credentials to force the organization’s domain controller to authenticate to the CISA-operated machine and then used Certipy to relay the coerced authentication attempt to the ADCS web enrollment service to receive a valid certificate for ACCOUNT 5, the domain controller machine account. They used this certificate to acquire a TGT [T1558] for ACCOUNT 5.
With the TGT for ACCOUNT 5, the CISA team used DCSync to dump the NTLM hash [T1003.006] for ACCOUNT 3 (a Domain Administrator account [see Attack Path 2 section]), effectively leading to domain compromise.
Attack Path 4
The CISA team identified several systems on the organization’s network that do not enforce SMB signing. The team exploited this misconfiguration to obtain cleartext credentials for two domain administrator accounts.
First, the team used Responder to capture the NTLMv2 hash for a domain administrator account. Next, they used Impacket’s NTLMrelayx tool[9] to relay the authentication for the domain administrator, opening a SOCKS connection on a host that did not enforce SMB signing. The team then used DonPAPI[10] to dump cleartext credentials through the SOCKS connection and obtained credentials for two additional domain administrator accounts.
The CISA team validated the privileges of these accounts by checking for READ,WRITE access on a domain controller C$ share [T1039], demonstrating Domain Administrator access and therefore domain compromise.
Attack Path 5
The team did vulnerability scanning [T1046] and identified a server vulnerable to CVE-2017-0144 (an Improper Input Validation [CWE-20] vulnerability known as “EternalBlue” that affects SMB version 1 [SMBv1] and enables remote code execution [see Figure 4]).
Figure 4: Checking for EternalBlue VulnerabilityThe CISA assessment team then executed a well-known EternalBlue exploit [T1210] and established a shell on the server. This shell allowed them to execute commands [T1059.003] under the context of the local SYSTEM account.
With this local SYSTEM account, CISA dumped password hashes from a Security Account Manager (SAM) database [T1003.002]. The team parsed the hashes and identified one for a local administrator account. Upon parsing the contents of the SAM database dump, the CISA team identified an NTLM hash for the local administrator account, which can be used to authenticate to various services.
The team sprayed the acquired NTLM hash across a network segment and identified multiple instances of password reuse allowing the team to access various resources including sensitive information with the hash.
Findings
Key Issues
The CISA assessments team identified several findings as potentially exploitable vulnerabilities that could compromise the confidentiality, integrity, and availability of the tested environment. Each finding, listed below, includes a description with supporting details. See the Mitigations section for recommendations on how to mitigate these issues.
The CISA team rated their findings on a severity scale from critical to informational (see Table 2).
Table 2: Severity Rating Criteria
Severity
Description
Critical
Critical vulnerabilities pose an immediate and severe risk to the environment because of the ease of exploitation and potential impact. Critical items are reported to the customer immediately.
High
Malicious actors may be able to exercise full control on the targeted device.
Medium
Malicious actors may be able to exercise some control of the targeted device.
Low
The vulnerabilities discovered are reported as items of interest but are not normally exploitable. Many low items reported by security tools are not included in this report because they are often informational, unverified, or of minor risk.
Informational
These vulnerabilities are potential weaknesses within the system that cannot be readily exploited. These findings represent areas that the customer should be cognizant of, but do not require any immediate action.
The CISA assessment team identified four High severity vulnerabilities and one Medium severity vulnerability during penetration testing that contributed to the team’s ability to compromise the domain. See Table 3 for a list and description of these findings.
Table 3: Key Issues Contributing to Domain Compromise
Issue
Severity
Service
Description
Poor Credential Hygiene: Easily Crackable Passwords
High
Penetration Testing
As part of their assessment, the team reviewed the organization’s domain password policy and found it was weak because the minimum password length was set to 8 characters. Passwords less than 15 characters without randomness are easily crackable, and malicious actors with minimal technical knowledge can use these credentials to access the related services.
The assessment team was able to easily crack many passwords throughout the assessment to move laterally and increase access within the domain. Specifically, the team:
Cracked the NTLMv2 hash for a domain account, and subsequently accessed the domain. (See the Attack Path 1 section.)
Cracked the password hash (obtained via Kerberoasting) of a domain administrator account and subsequently compromised the domain. (See the Attack Path 1 section.)
Poor Credential Hygiene: Guessable Credentials
High
Penetration Testing
As part of the penetration test, the assessment team tested to see if one or more services is accessible using a list of enumerated usernames alongside an easily guessed password. The objective is to see if a malicious actor with minimal technical knowledge can use these credentials to access the related services, enabling them to move laterally or escalate privileges. Easily guessable passwords are often comprised of common words, seasons, months and/or years, and are sometimes combined with special characters. Additionally, phrases or names that are popular locally (such as the organization being tested or a local sports teams) may also be considered easily guessable.
The team sprayed common passwords against domain user accounts and obtained valid credentials for standard domain users. (See the Attack Path 3 section.) (Cracking was not necessary for this attack.)
Misconfigured ADCS Certificate Templates
High
Penetration Testing
The team identified a WebServer template configured to allow all authenticated users permission to change the properties of the template and obtain certificates for different users. The team exploited the template to acquire a certificate for a Domain Administrator account (see the Attack Path 2 section).
Unnecessary Network Services Enabled
High
Penetration Testing
Malicious actors can exploit security vulnerabilities and misconfigurations in network services, especially legacy services.
The assessment team identified legacy name resolution protocols (e.g., NetBIOS, LLMNR, mDNS) enabled in the network, and abused LLMNR to capture NTLMv2 hashes, which they then cracked and used for domain access. (See the Attack Path 1 section.)
The team also identified an ADCS server with web enrollment enabled and leveraged it to compromise the domain through coercion and relaying. (See Attack Path 3 section.)
Additionally, the team identified hosts with WebClient and Spooler services, which are often abused by malicious actors to coerce authentication.
Elevated Service Account Privileges
High
Penetration Testing
Applications often require user accounts to operate. These user accounts, which are known as service accounts, often require elevated privileges. If an application or service running with a service account is compromised, an actor may have the same privileges and access as the service account.
The CISA team identified a service account with Domain Administrator privileges and used it to access the domain after cracking its password (See the Attack Path 1 section).
SMB Signing Not Enabled
High
Penetration Testing
The CISA team identified several systems on the organization’s network that do not enforce SMB signing and exploited this for relayed authentication to obtain cleartext credentials for two domain administrator accounts.
Insecure Default Configuration: Default Credentials
Medium
Web Application Assessment
Many off-the-shelf applications are released with built-in administrative accounts using predefined credentials that can often be found with a simple web search. Malicious actors with minimal technical knowledge can use these credentials to access the related services.
During testing, the CISA team identified multiple web interfaces with default administrator credentials and used default credentials for a printer interface to capture domain credentials of a non-privileged domain account. (See the Attack Path 2 section.)
In addition to the issues listed above, the team identified three High and seven Medium severity findings. These vulnerabilities and misconfigurations may allow a malicious actor to compromise the confidentiality, integrity, and availability of the tested environment. See Table 4 for a list and description of these findings.
Table 4: Additional Key Issues
Issue
Severity
Service
Description
Poor Credential Hygiene: Password Reuse for Administrator and User Accounts
High
Penetration Testing
Elevated password reuse is when an administrator uses the same password for their user and administrator accounts. If the user account password is compromised, it can be used to gain access to the administrative account.
The assessment team identified an instance where the same password was set for an admin user’s administrative account as well as their standard user account.
Poor Credential Hygiene: Password Reuse for Administrator Accounts
Medium
Penetration Testing
If administrator passwords are the same for various administrator accounts, malicious actors can use the password to access all systems that share this credential after compromising one account.
The assessment team found multiple instances of local administrator accounts across various systems using the same password.
Poor Patch Management: Out-of-Date Software
High
Penetration Testing
Patches and updates are released to address existing and emerging security vulnerabilities, and failure to apply the latest leaves systems open to attack with publicly available exploits. (The risk presented by missing patches and updates depends on the severity of the vulnerability).
The assessment team identified several unpatched systems including instances of CVE-2019-0708 (known as “BlueKeep”) and EternalBlue.
The team was unable to successfully compromise the systems with BlueKeep, but they did exploit EternalBlue on a server to implant a shell on a server with local SYSTEM privileges (see the Attack Path 5 section).
Poor Patch Management: Unsupported OS or Application
High
Penetration Testing
Using software or hardware that is no longer supported by the vendor poses a significant security risk because new and existing vulnerabilities are no longer patched). There is no way to address security vulnerabilities on these devices to ensure that they are secure. The overall security posture of the entire network is at risk because an attacker can target these devices to establish an initial foothold into the network.
The assessment team identified end-of-life (EOL) Windows Server 2008 R2 and Windows Server 2008 and Windows 5.1.
Use of Weak Authentication Measures
Medium
Penetration Testing
Applications may have weak or broken mechanisms to verify user identity before granting user access to protected functionalities. Malicious actors can exploit these to bypass authentication and gain access to use application resources and functionality.
The assessment team abused the Cisco Smart Install protocol to obtain configuration files for several Cisco devices on the organization’s network. These files contained encrypted Cisco passwords. (The CISA team was unable to crack these passwords within the assessment timeframe.)
PII Disclosure
Medium
Penetration Testing
The assessment team identified an unencrypted Excel file containing PII on a file share.
Hosts with Unconstrained Delegation Enabled Unnecessarily
Medium
Penetration Testing
The CISA team identified two systems that appeared to be configured with Unconstrained Delegation enabled. Hosts with Unconstrained Delegation enabled store the Kerberos TGTs of all users that authenticate to that host, enabling actors to steal service tickets or compromise krbtgt accounts and perform golden ticket or silver ticket attacks.
Although the assessment team was unable to fully exploit this configuration because they lost access to one of the vulnerable hosts, it could have led to domain compromise under the right circumstances.
Cleartext Password Disclosure
Medium
Penetration Testing
Storing passwords in cleartext is a security risk because malicious actors with access to these files can use them.
The assessment team identified several unencrypted files on a file share containing passwords for various personal and organizational accounts.
Insecure File Shares
Medium
Penetration Testing
Access to sensitive data (e.g., data related to business functions, IT functions, and/or personnel) should be restricted to only certain authenticated and authorized users.
The assessment team found an unsecured directory on a file share with sensitive IT information. The directory was accessible to all users in the domain group. Malicious actors with user privileges could access and/or exfiltrate this data.
Additional Issues
The CISA team identified one Informational severity within the organization’s networks and systems. These issues may allow a malicious actor to compromise the confidentiality, integrity, and availability of the tested environment, but are not readily exploitable. The information provided is to encourage the stakeholder to investigate these issues further to adjust their environments or eliminate certain aspects as needed, but the urgency is low.
Table 5: Informational Issues That CISA Team Noted
Issue
Severity
Service
Description
Overly Permissive Accounts
Informational
Penetration Testing
Account privileges are intended to control user access to host or application resources to limit access to sensitive information in support of a least-privilege security model. When user (or other) accounts have high privileges, users can see and/or do things they normally should not, and malicious actors can exploit this to access host and application resources.
The assessment team identified Active Directory objects where the Human Resources group appeared to be part of the privileged Account Operators group. This may have provided elevated privileges to accounts in the Human Resources group. (The CISA team was unable to validate and demonstrate the potential impact of this relationship within the assessment period).
Noted Strengths
The CISA team noted the following business, technical, and administrative components that enhanced the network security posture of the tested environment:
The organization’s network was found to have several strong, security-oriented characteristics such as:
Effective antivirus software;
Endpoint detection and response capabilities;
Good policies and best practices for protecting users from malicious files including not allowing users to mount ISO files;
Minimal external attack surface, limiting an adversary’s ability to leverage external vulnerabilities to gain initial access to the organization’s networks and systems;
Strong wireless protocols;
And network segmentation.
The organization’s security also demonstrated their ability to detect some of the CISA team's actions throughout testing and overall situational awareness through the use of logs and alerts.
The organization used MFA for cloud accounts. The assessment team obtained cloud credentials via a phishing campaign but was unable to use them because of MFA prompts.
MITIGATIONS
Network Defenders
CISA recommends HPH Sector and other critical infrastructure organizations implement the mitigations in Table 6 to mitigate the issues listed in the Findings section of this advisory. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.
Table 6: Recommendations to Mitigate Identified Issues
Issue
Recommendation
Poor Credential Hygiene: Easily Crackable Passwords
Follow National Institute of Standards and Technologies (NIST) guidelines when creating password policies to enforce use of “strong” passwords that cannot be cracked [CPG 2.B].[11] Consider using password managers to generate and store passwords.
Use “strong” passphrases for private keys to make cracking resource intensive [CPG 2.B]. Do not store credentials within the registry in Windows systems. Establish an organizational policy that prohibits password storage in files.
Ensure adequate password length (ideally 15+ characters) and complexity requirements for Windows service accounts and implement passwords with periodic expiration on these accounts [CPG 2.B]. Use Managed Service Accounts, when possible, to manage service account passwords automatically.
Poor Credential Hygiene: Guessable Credentials
Do not reuse local administrator account passwords across systems. Ensure that passwords are “strong” and unique [CPG 2.C].
Use phishing-resistant multi-factor authentication (MFA) for all administrative access, including domain administrative access [CPG 2.H]. If an organization that uses mobile push-notification-based MFA is unable to implement phishing-resistant MFA, use number matching to mitigate MFA fatigue. For more information, see CISA fact sheets on Implementing Phishing-Resistant MFA and Implementing Number Matching in MFA Applications.
Misconfigured ADCS Certificate Templates
Restrict enrollment rights in templates to only those users or groups that require it. Remove the Enrollee Supplies Subject flag from templates if it is not necessary or enforce manager approval if required. Consider removing Write Owner, Write DACL and Write Property permissions from low-privilege groups, such as Authenticated Users where those permissions are not needed.
Unnecessary Network Services Enabled
Ensure that only ports, protocols, and services with validated business needs are running on each system. Disable deprecated protocols (including NetBIOS, LLMNR, and mDNS) on the network that are not strictly necessary for business functions, or limit the systems and services that use the protocol, where possible [CPG 2.W].
Disable the WebClient and Spooler services where possible to minimize risk of coerced authentication.
Disable ADCS web-enrollment services. If this service cannot be disabled, disable NTLM authentication to prevent malicious actors from performing NTLM relay attacks or abusing the Spooler and WebClient services to coerce and relay authentication to the web-enrollment service.
Elevated Service Account Privileges
Run daemon applications using a non-Administrator account when appropriate.
Configure Service accounts with only the permissions necessary for the services they operate.
To mitigate Kerberoasting attacks, use AES or stronger encryption instead of RC4 for Kerberos hashes [CPG 2.K]. RC4 is considered weak encryption.
SMB Signing Not Enabled
Require SMB signing for both SMB client and server on all systems to prevent certain adversary-in-the-middle and pass-the-hash attacks. See Microsoft’s Overview of Server Message Block signing for more information.
Insecure Default Configuration: Default Credentials
Verify the implementation of appropriate hardening measures, and change, remove, or deactivate all default credentials [CPG 2.A].
Before deploying any new devices in a networked environment, change all default passwords for applications, operating systems, routers, firewalls, wireless access points, and other systems to have values consistent with administration-level accounts [CPG 2.A].
Poor Credential Hygiene: Password Reuse for Administrator and User Accounts
Discontinue reuse or sharing of administrative credentials among user/administrative accounts [CPG 2.C].
Use unique credentials across workstations, when possible, in accordance with applicable federal standards, industry best practices, and/or agency-defined requirements.
Train users, especially privileged users, against password reuse [CPG 2.I].
Poor Credential Hygiene: Password Reuse for Administrator Accounts
Discontinue reuse or sharing of administrative credentials among systems [CPG 2.C]. When possible, use unique credentials across all workstations in accordance with applicable federal standards, industry best practices, and/or agency-defined requirements.
Implement a security awareness program that focuses on the methods commonly used in intrusions that can be blocked through individual action [CPG 2.I].
Implement Local Administrator Password Solution (LAPS) where possible if your OS is older than Windows Server 2019 and Windows 10 as these versions do not have LAPS built in. Note: The authoring organizations recommend organizations upgrade to Windows Server 2019 and Windows 10 or greater.
Poor Patch Management: Out-of-Date Software
Enforce consistent patch management across all systems and hosts within the network environment [CPG 1.E].
Where patching is not possible due to limitations, implement network segregation controls [CPG 2.F] to limit exposure of the vulnerable system or host.
Consider deploying automated patch management tools and software update tools for operating system and software/applications on all systems for which such tools are available and safe.
Poor Patch Management: Unsupported OS or Application
Evaluate the use of unsupported hardware and software and discontinue where possible. If discontinuing the use of unsupported hardware and software is not possible, implement additional network protections to mitigate the risk.
Use of Weak Authentication Measures
Require phishing-resistant MFA for all user accounts that have access to sensitive data or systems. If MFA is not possible, it is recommended to, at a minimum, configure a more secure password policy by aligning with guidelines put forth by trusted entities such as NIST [CPG 2.H].
PII Disclosure
Implement a process to review files and systems for insecure handling of PII [CPG 2.L]. Properly secure or remove the information. Conduct periodic scans of server machines using automated tools to determine whether sensitive data (e.g., personally identifiable information, health, credit card, or classified information) is present on the system in cleartext.
Encrypt PII and other sensitive data, and train users who handle sensitive data to utilize best practices for encrypting data and storing it securely. If sensitive data must be stored on shares or other locations, restrict access to these locations as much as possible through access controls and network segmentation [CPG 2.F, 2.K, 2.L].
Hosts with Unconstrained Delegation Enabled Unnecessarily
Remove Unconstrained Delegation from all servers. If Unconstrained Delegation functionality is required, upgrade operating systems and applications to leverage other approaches (e.g., configure Constrained Delegation, enable the Account is sensitive and cannot be delegated option) or explore whether systems can be retired or further isolated from the enterprise. CISA recommends Windows Server 2019 or greater.
Cleartext Password Disclosure
Implement a review process for files and systems to look for cleartext account credentials. When credentials are found, remove or change them to maintain security [CPG 2.L].
Conduct periodic scans of server machines using automated tools to determine whether sensitive data (e.g., personally identifiable information, health, credit card, or classified information) is present on the system in cleartext. Consider implementing a secure password manager solution in cases where passwords need to be stored [CPG 2.L].
Insecure File Shares
Restrict access to file shares containing sensitive data to only certain authenticated and authorized users [CPG 2.L].
Additionally, CISA recommends that HPH sector organizations implement the following strategies to mitigate cyber threats:
Mitigation Strategy #1 Asset Management and Security:
CISA recommends that HPH sector organizations implement and maintain an asset management policy to reduce the risk of exposing vulnerabilities, devices, or services that could be exploited by threat actors to gain unauthorized access, steal sensitive data, or disrupt critical services. The focus areas for this mitigation strategy include asset management and asset security, addressing asset inventory, procurement, decommissioning, and network segmentation as they relate to hardware, software, and data assets.
Mitigation Strategy #2 Identity Management and Device Security:
CISA recommends entities secure their devices and digital accounts and manage their online access to protect sensitive data and PII/PHI from compromise. The focus areas for this mitigation strategy include email security, phising prevention, access management, password policies, data protection and loss prevention, and device logs and monitoring solutions.
Mitigation Strategy #3 Vulnerability, Patch, and Configuration Management:
CISA recommends entities mitigate known vulnerabilities and establish secure configuration baselines to reduce the likelihood of threat actors exploiting known vulnerabilities to breach organizational networks. The focus areas for this mitigation strategy include vulnerability and patch Management, and configuration and change management.
For more information on these mitigations strategies, see CISA’s Healthcare and Public Health Sector webpage.
Software Manufacturers
The above mitigations apply to HPH sector and other critical infrastructure organizations with on-premises or hybrid environments. Recognizing that insecure software is the root cause of the majority of these flaws, and that the responsibility should not be on the end user, CISA urges software manufacturers to implement the following to reduce the prevalence of misconfigurations, weak passwords, and other weaknesses identified and exploited through the assessment team:
Embed security into product architecture throughout the entire software development lifecycle (SDLC).
Eliminate default passwords. Do not provide software with default passwords. To eliminate default passwords, require administrators set a “strong” password [CPG 2.B] during installation and configuration.
Create secure configuration templates. Provide configuration templates with certain safe settings based on an organization’s risk appetite (e.g., low, medium, and high security templates). Support these templates with hardening guides based on the risks the manufacturer has identified. The default configuration should be a secure one, and organizations should need to opt in if they desire a less secure configuration.
Design products so that the compromise of a single security control does not result in compromise of the entire system. For example, narrowly provision user privileges by default and employ ACLs to reduce the impact of a compromised account. This will make it more difficult for a malicious cyber actor to escalate privileges and move laterally.
Mandate MFA, ideally phishing-resistant MFA, for privileged users and make MFA a default, rather than opt-in, feature.
These mitigations align with tactics provided in the joint guide Shifting the Balance of Cybersecurity Risk: Principles and Approaches for Secure by Design Software. CISA urges software manufacturers to take ownership of improving the security outcomes of their customers by applying these and other secure by design tactics. By using secure by design tactics, software manufacturers can make their product lines secure “out of the box” without requiring customers to spend additional resources making configuration changes, purchasing security software and logs, monitoring, and making routine updates.
For more information on secure by design, see CISA’s Secure by Design webpage. For more information on common misconfigurations and guidance on reducing their prevalence, see the joint advisory NSA and CISA Red and Blue Teams Share Top Ten Cybersecurity Misconfigurations.
VALIDATE SECURITY CONTROLS
In addition to applying the listed mitigations, CISA recommends exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA recommends testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.
To get started:
Select an ATT&CK technique described in this advisory (see Tables 7 – 16).
Align your security technologies against the technique.
Test your technologies against the technique.
Analyze your detection and prevention technologies’ performance.
Repeat the process for all security technologies to obtain a set of comprehensive performance data.
Tune your security program, including people, processes, and technologies, based on the data generated by this process.
CISA recommends continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.
RESOURCES
For consolidated findings from the RVAs by Fiscal Year mapped to MITRE ATT&CK, see CISA’s Risk and Vulnerability Assessments page.
See joint CSA NSA and CISA Red and Blue Teams Share Top Ten Cybersecurity Misconfigurations for information on the most common cybersecurity misconfigurations in large organizations and TTPs actors use to exploit these misconfigurations.
See CISA’s Healthcare and Public Health Sector webpage.
See CISA’s RedEye tool on CISA’s GitHub page. RedEye is an interactive open-source analytic tool used to visualize and report red team command and control activities. See CISA’s RedEye tool overview video for more information.
REFERENCES
[1] Github | kgretzky / evilginx
[2] Github | lgandx / Responder
[3] Network security LAN Manager authentication level - Windows Security | Microsoft Learn
[4] Service principal names - Win32 apps | Microsoft Learn
[5] Github | fortra / impacket
6] Github | byt3bl33d3r / CrackMapExec
[7] Github | ly4k / Certipy
[8] Github | topotam / PetitPotam
[9] Github | fortra / impacket / examples
[10] Github | login-securite / DonPAPI
[11] SP 800-63B, Digital Identity Guidelines: Authentication and Lifecycle Management | CSRC (nist.gov)
APPENDIX: MITRE ATT&CK TACTICS AND TECHNIQUES
Table 7: CISA Team ATT&CK Techniques for Reconnaissance
Reconnaissance
Technique Title
ID
Use
Active Scanning: Scanning IP Blocks
T1595.001
The CISA team first mapped the network to identify open web ports.
Table 8: CISA Team ATT&CK Techniques for Initial Access
Initial Access
Technique Title
ID
Use
Valid Accounts: Default Accounts
T1078.001
The CISA team did identify default credentials for multiple web interfaces during web application testing and used default printer credentials while penetration testing.
External Remote Services
T1133
The CISA team attempted to access various web interfaces with default administrator credentials.
Table 9: CISA Team ATT&CK Techniques for Execution
Execution
Technique Title
ID
Use
Command-Line Interface
T1059
The CISA team accessed a virtual machine interface enabling them to modify, power off, and/or delete critical virtual machines including domain controllers, file servers, and servers.
Command and Scripting Interpreter: Windows Command Shell
T1059.003
The CISA team used a webshell that allowed them to execute commands under the context of the local SYSTEM account.
Table 10: CISA Team ATT&CK Techniques for Privilege Escalation
Privilege Escalation
Technique Title
ID
Use
Valid Accounts: Domain Accounts
T1078.002
The CISA team used CrackMapExec to use ACCOUNT 1 to successfully connect to a domain controller (DC).
Table 11: CISA Team ATT&CK Techniques for Defense Evasion
Defense Evasion
Technique Title
ID
Use
Use Alternate Authentication Material
T1550
The CISA team authenticated to the domain controller as ACCOUNT 3 with the generated certificate.
Table 12: CISA Team ATT&CK Techniques for Credential Access
Credential Access
Technique Title
ID
Use
LLMNR/NBT-NS Poisoning and Relay
T1557.001
The CISA team initiated a LLMNR/NBT-NS/mDNS/DHCP poisoning tool to spoof a connection to the organization’s server for forced access.
Brute Force: Password Cracking
T1110.002
The CISA team cracked a service account with a weak password, giving them access to it.
Steal or Forge Kerberos Tickets: Kerberoasting
T1558.003
The CISA team gained access to domain accounts because any domain user can request a TGS ticket for domain accounts.
Adversary-in-the-Middle
T1557
The CISA team modified the “Save as file” configuration, to use File Transfer Protocol (FTP) instead of Server Message Block (SMB) and changed the Server Name and Network Path to point to a CISA-controlled machine running Responder.
Forced Authentication
T1187
The CISA team executed a “Connection Test” that sent the username and password over FTP.
Steal or Forge Authentication Certificates
T1649
The CISA team used Certipy to enumerate the ADCS certificate template vulnerabilities, allowing them to obtain certificates for different users.
OS Credential Dumping
T1003
The CISA team retrieved the NTLM hash for ACCOUNT 3.
Use Alternate Authentication Material: Pass the Hash
T1550.002
The CISA team used the hash to authenticate to the domain controller and validated Domain Administrator privileges, demonstrating compromise of the domain.
Brute Force: Password Spraying
T1110.003
The CISA team used a tool called CrackMapExec to spray easily guessable passwords across all domain accounts, giving them two sets of valid credentials.
Steal or Forge Kerberos Tickets
T1558
The CISA team used this certificate to acquire a TGT for ACCOUNT 5.
OS Credential Dumping: DCSync
T1003.006
The CISA team used DCSync to dump the NTLM hash for ACCOUNT 3 (a Domain Administrator account), effectively leading to domain compromise.
OS Credential Dumping: Security Account Manager
T1003.002
The CISA team dumped password hashes from a Security Account Manager (SAM) database.
Table 13: CISA Team ATT&CK Techniques for Discovery
Discovery
Technique Title
ID
Use
Network Sniffing
T1040
The CISA team spoofed a response to direct the victim host to a CISA-controlled machine on which Responder is running.
Account Discovery: Domain Account
T1087.002
The CISA team enumerated accounts with a Service Principal Name (SPN) set with their domain access.
Network Service Scanning
T1046
The CISA team canned the organization’s network to identify open web ports to see where they could leverage the default credentials they had.
Table 14: CISA Team ATT&CK Techniques for Lateral Movement
Lateral Movement
Technique Title
ID
Use
Remote Services
T1021
The CISA team exploited its Responder to perform malicious functions, such as stealing credentials or opening a session on a targeted host.
SMB/Windows Admin Shares
T1021.002
The CISA team confirmed they compromised the domain because ACCOUNT 1 had READ,WRITE permissions over the C$ administrative share.
Taint Shared Content
T1080
The CISA team found the device was configured with domain credentials to allow employees to save scanned documents to a network share.
Exploitation of Remote Services
T1210
The CISA team then executed a well-known EternalBlue exploit and established a shell on the server.
Table 15: CISA Team ATT&CK Techniques for Collection
Collection
Technique Title
ID
Use
Data from Network Shared Drive
T1039
The CISA team obtained credentials for cleartext, hashes, and from files.
Table 16: CISA Team ATT&CK Techniques for Impact
Collection
Technique Title
ID
Use
System Shutdown/Reboot
T1529
The CISA team assessed that with ACCOUNT 1, they could use it to modify, power off, and/or delete critical virtual machines, including domain controllers and file servers.
VERSION HISTORY
December 14, 2023: Initial version.