Multiple Nation-State Threat Actors Exploit CVE-2022-47966 and CVE-2022-42475

SUMMARY

The Cybersecurity and Infrastructure Security Agency (CISA), Federal Bureau of Investigation (FBI), and Cyber National Mission Force (CNMF) identified the presence of indicators of compromise (IOCs) at an Aeronautical Sector organization as early as January 2023. Analysts confirmed that nation-state advanced persistent threat (APT) actors exploited CVE-2022-47966 to gain unauthorized access to a public-facing application (Zoho ManageEngine ServiceDesk Plus), establish persistence, and move laterally through the network. This vulnerability allows for remote code execution on the ManageEngine application. Additional APT actors were also observed exploiting CVE-2022-42475 to establish presence on the organization’s firewall device.

CISA and co-sealers are releasing this joint Cybersecurity Advisory (CSA) to provide network defenders with tactics, techniques, and procedures (TTPs), IOCs, and methods to detect and protect against similar exploitation.

Download the PDF version of this report:

For a downloadable copy of IOCs, see:

For a downloadable copy of the Malware Analysis Report (MAR) accompanying this CSA, see:

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 13. See Tables 3-13 for the APT actors’ activity mapped to MITRE ATT&CK tactics and techniques with corresponding mitigation and/or detection recommendations.

Overview

By request of the impacted organization, CISA conducted an incident response engagement from February to April 2023. CISA and co-sealers assess that beginning as early as January 2023, multiple nation-state APT actors were present on the organization’s network via at least two initial access vectors:

• Initial Access Vector 1: APT actors exploited CVE-2022-47966 to access the organization’s web server hosting the public-facing application, Zoho ManageEngine ServiceDesk Plus.
• Initial Access Vector 2: APT actors exploited CVE-2022-42475 to access the organization’s firewall device.

CISA and co-sealers identified an array of threat actor activity, to include overlapping TTPs across multiple APT actors. Per the activity conducted, APT actors often scan internet-facing devices for vulnerabilities that can be easily exploited. Firewall, virtual private networks (VPNs), and other edge network infrastructure continue to be of interest to malicious cyber actors. When targeted, they can be leveraged to expand targeted network access, serve as malicious infrastructure, or a mixture of both.

APT Actor Activity

Initial Access Vector 1

As early as January 2023, APT actors exploited CVE-2022-47966 [T1190] for initial access to the organization’s web server hosting the public-facing application, Zoho ManageEngine ServiceDesk Plus. CISA observed indications in log files that a connection to the known malicious IP address 192.142.226[.]153 was made as part of initial exploitation.

Through exploitation of CVE-2022-47966, APT actors achieved root level access on the web server and created a local user account [T1136.001] named Azure with administrative privileges [T1068]. Actors were further able to download malware, enumerate the network, collect administrative user credentials, and move laterally through the organization’s network. CISA and co-sealers were unable to determine if proprietary information was accessed, altered, or exfiltrated. This was due to the organization not clearly defining where their data was centrally located and CISA having limited network sensor coverage.

Initial Access Vector 2

Additional APT actors exploited CVE-2022-42475 on the organization’s firewall device, which was indicated by multiple successful VPN connections from known-malicious IPs between February 1-16, 2023. It was identified that APT actors compromised and used disabled, legitimate administrative account credentials [T1078.003] from a previously hired contractor—of which the organization confirmed the user had been disabled prior to the observed activity.

Analysis identified that a common behavior for these threat actors was to use disabled administrative account credentials and delete logs from several critical servers in the environment [T1070.001]. This prevented the ability to detect follow-on exploitation or data exfiltration. CISA and co-sealers were also unable to further track the activity due to the organization not having Network Address Translation (NAT) IP logging enabled.

APT actors initiated multiple Transport Layer Security (TLS)-encrypted sessions [T1573.002] on Transmission Control Protocol (TCP) port 10443 [T1571], indicating successful exchanges of data transfer from the firewall device. APT actors were observed connecting to the device from the following actor-controlled C2 IP addresses:

• 144.202.2[.]71
• 207.246.105[.]240
• 45.77.121[.]232
• 47.90.240[.]218

APT actors further leveraged legitimate credentials to move from the firewall to a web server, where multiple web shells were loaded—among other locations, such as the OWA server—into the following directories. Note: The following file paths to these web shells were received in coordination with a trusted third-party; however, the artifacts were not received for analysis.

• c:\Program Files\Microsoft Office Web Apps\RootWebsite\en-us\resource.aspx
• c:\inetpub\wwwroot\[REDACTED]\css\font-awesome\css\discover.ashx
• c:\inetpub\wwwroot\[REDACTED]\css\font-awesome\css\configlogin.ashx
• c:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\15\template\layouts\approveinfo.aspx
• c:\Program Files\Microsoft Office Web Apps\RootWebsite\infos.aspx
• c:\Program Files\Microsoft Office Web Apps\RootWebsite\errorinfo.aspx
• c:\Program Files\Microsoft Office Web Apps\RootWebsite\infos.ashx
• c:\Program Files\Microsoft Office Web Apps\RootWebsite\en-us\error.aspx
• c:\Program Files\Microsoft Office Web Apps\RootWebsite\en-us\infos.aspx
• c:\Program Files\Microsoft Office Web Apps\RootWebsite\en-us\info.aspx
• c:\Program Files\Microsoft Office Web Apps\RootWebsite\en-us\info-1.aspx
• c:\Program Files\Microsoft Office Web Apps\RootWebsite\en-us\new_list.aspx
• c:\Program Files\Microsoft Office Web Apps\RootWebsite\en-us\errorinfo.aspx
• c:\Program Files\Microsoft Office Web Apps\RootWebsite\en-us\lgnbotr.ashx
• c:\inetpub\passwordchange\0LECPNJYRH.aspx
• c:\inetpub\passwordchange\9ehj.aspx
• c:\inetpub\wwwroot\wss\VirtualDirectories\Portal80\_vti_pvt\servicesinfo.ashx
• c:\inetpub\wwwroot\wss\VirtualDirectories\Portal80\_vti_pvt\services.aspx
• c:\inetpub\redirectedSites\[REDACTED]\products\uns1fw.aspx
• c:\inetpub\redirectedSites\[REDACTED]\products\uns1ew.aspx

The following IP addresses were identified as associated with the loaded web shells:

• 45.90.123[.]194
• 154.6.91[.]26
• 154.6.93[.]22
• 154.6.93[.]5
• 154.6.93[.]12
• 154.6.93[.]32
• 154.6.93[.]24
• 184.170.241[.]27
• 191.96.106[.]40
• 102.129.145[.]232

Forensic Timeline of APT Actor Activity

Tables 1 and 2 list the timeline of events discovered during the incident response, as well as tools used by the APT actors to conduct their operations, respectively. All timestamps are presented in Coordinated Universal Time (UTC).

Post-engagement analysis was extended but analysts were unable to determine additional actions taken by the APT actors, likely due to a lack of sensor coverage and data unavailability. With the data available, it was determined APT actors used the tools listed in Table 2 during their operations.

MITRE ATT&CK TACTICS AND TECHNIQUES

See Tables 3-13 for all referenced APT actors’ tactics and techniques for enterprise environments in this advisory. 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.

DETECTION METHODS

CISA and co-sealers recommend reviewing Tables 3-13: Identified ATT&CK Techniques for Enterprise in conjunction with the detections in this section to identify similar activity.

• Enable logging for new user creation [DS0002], as well as monitor executed commands and arguments for actions that are associated with local account creation, such as net user /add, useradd, and dscl -create [DS0017].
• Monitor for newly constructed scheduled tasks by enabling the "Microsoft-Windows-TaskScheduler/Operational" setting within the event logging service. Monitor for changes made to scheduled tasks that may attempt to manipulate features of their artifacts to make them appear legitimate or benign to users and/or security tools [DS0003].
• Monitor for API calls that may create or modify Windows services (ex: CreateServiceW()) to repeatedly execute malicious payloads as part of persistence [DS0009].
• Monitor executed commands and arguments that may attempt to access credential material stored in the process memory of the LSASS [DS0017].
• Monitor for user accounts logged into systems associated with RDP (ex: Windows EID 4624 Logon Type 10) [DS0028].
• Monitor for newly-constructed network connections associated with pings/scans that may attempt to collect a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for lateral movement from the current system [DS0029].
• Conduct full port scans (1-65535) on internet-facing systems—not just a subset of the ports.

MITIGATIONS

Note: 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.

Manage Vulnerabilities and Configurations [CPG 1.E, CPG 3.A]

CISA and co-sealers identified that exploitation of CVE-2022-47966 granted initial access to the public-facing application, Zoho ManageEngine ServiceDesk Plus. Multiple Zoho ManageEngine on-premises products, such as ServiceDesk Plus through 14003, allow remote code execution due to use of version 1.4.1 of Apache XML Security for Java (also known as xmlsec) from the Apache Santuario project. Due to the xmlsec XSLT features by design in that version, the application is responsible for certain security protections. CISA and co-sealers recommend the following:

• Document device configurations [CPG 2.O]. Organizations should maintain updated documentation describing the current configuration details of all critical IT assets (and OT, where applicable), as this facilitates more effective vulnerability and response activities.
• Keep all software up to date and patch systems for known exploited vulnerabilities. In places with known exploited vulnerabilities on an endpoint device (e.g., firewall security appliances), conduct investigation prior to patching [CPG 1.E].
• Follow a routine patching cycle [M1051] for all operating systems, applications, and software (including all third-party software) to mitigate the potential for exploitation.
• Prioritize remediation of vulnerabilities on internet-facing systems, for example, by conducting continuous automated and/or routine vulnerability scans [M1016]. CISA offers a range of services at no cost, including scanning and testing to help organizations reduce exposure to threats via mitigating attack vectors. Specifically, Cyber Hygiene services can help provide a second-set of eyes on organizations' internet-accessible assets. Organizations can email vulnerability@cisa.dhs.gov with the subject line, “Requesting Cyber Hygiene Services” to get started. For additional guidance on remediating these vulnerabilities, see CISA Insights - Remediate Vulnerabilities for Internet-Accessible Systems.
• Deploy security.txt files [CPG 4.C]. All public-facing web domains have a security.txt file that conforms to the recommendations in RFC 9116.[9]

Segment Networks [CPG 2.F]

CISA and co-sealers identified that the organization did not employ proper network segmentation, such as a demilitarized zone (DMZ), during the initial discovery phase of the incident response. A DMZ serves as a perimeter network that protects and adds an extra layer of security to an organization’s internal local area network (LAN) from untrusted traffic.

• Employ proper network segmentation, such as a DMZ, and ensure to address the following recommendations. Note: The end goal of a DMZ network is to allow an organization to access untrusted networks, such as the internet, while ensuring its private network or LAN remains secure. Organizations typically store external-facing services and resources, as well as servers for DNS, File Transfer Protocol (FTP), mail, proxy, Voice over Internet Protocol (VoIP), and web servers in the DMZ [CPG 2.K, CPG 2.W].
  • Limit internet-facing port exposure for critical resources in the DMZ networks.
  • Limit exposed ports to only required IP addresses and avoid placing wildcards in destination port or host entries.
  • Ensure unsecured protocols like FTP and HTTP are limited in use and restricted to specific IP ranges.
  • If data flows from untrusted zone to trusted zone, ensure it is conducted over a secure protocol like HTTPS with mandatory multi-factor authentication.
• Use a firewall or web-application firewall (WAF) and enable logging to prevent/detect potential exploitation attempts [M1050]. Review ingress and egress firewall rules and block all unapproved protocols. Limit risky (but approved) protocols through rules.
  • Use WAF to limit exposure to just approved ports, as well as monitor file changes in web directories.
• Implement network segmentation to separate network segments based on role and functionality. Proper network segmentation significantly reduces the ability for threat actor lateral movement by controlling traffic flows between—and access to—various subnetworks. See CISA’s Layering Network Security Through Segmentation infographic and the National Security Agency’s (NSA’s) Segment Networks and Deploy Application-Aware Defenses.

Manage Accounts, Permissions, and Workstations

APT actors were able to leverage disabled administrative accounts, as well as clear logs on several critical servers, which prevented the ability to detect follow-on exploitation or data exfiltration. CISA and co-sealers recommend the following:

• Use phishing-resistant multi-factor authentication (MFA) [CPG 2.H] (e.g., security tokens) for remote access and access to any sensitive data repositories. Implement phishing-resistant MFA for as many services possible—particularly for webmail and VPNs—for accounts that access critical systems and privileged accounts that manage backups. MFA should also be used for remote logins [M1032]. For additional guidance on secure MFA configurations, visit cisa.gov/MFA and CISA’s Implementing Phishing-Resistant MFA Factsheet.
• Employ strong password management alongside other attribute-based information, such as device information, time of access, user history, and geolocation data. Set a password policy to require complex passwords for all users (minimum of 16 characters) and enforce this new requirement as users’ passwords expire [CPG 2.A, CPG 2.B, CPG 2.C].
• Implement the principle of least privilege to decrease threat actors’ abilities to access key network resources.
• Limit the ability of a local administrator account to log in from a local interactive session [CPG 2.E] (e.g., “Deny access to this computer from the network”) and prevent access via an RDP session.
• Establish policy and procedure for the prompt removal of unnecessary (disabled) accounts and groups from the enterprise that are no longer needed, especially privileged accounts. Implement and enforce use of Local Administrator Password Solution (LAPS).
• Control and limit local administration, ensuring administrative users do not have access to other systems outside of the local machine and across the domain.
• Create a change control process for all privilege escalations and role changes on user accounts. Enable alerts on privilege escalations and role changes, as well as log privileged user changes in the network environment and create alerts for abnormal events.
• Create and deploy a secure system baseline image to all workstations. See Microsoft’s guidance on Using Security Baselines in Your Organization.
• Implement policies to block workstation-to-workstation RDP connections [CPG 2.V] through a Group Policy Object on Windows, or by a similar mechanism. The RDP service should be disabled if it is unnecessary [M1042].

Secure Remote Access Software

Remote access software provides a proactive and flexible approach for organizations to internally oversee networks, computers, and other devices; however, cyber threat actors increasingly co-opt these tools for access to victim systems. APT actors were observed using legitimate remote access tools—ConnectWise ScreenConnect and AnyDesk—to connect to victim hosts within the organization’s environment and further conduct malicious operations. CISA and co-sealers recommend the following:

• Establish a software behavior baseline to detect anomalies in behavior [CPG 2.T, CPG 2.U].
• Monitor for unauthorized use of remote access software using endpoint detection tools.

For more information, see CISA’s joint Guide to Securing Remote Access Software on best practices for using remote capabilities and how to detect and defend against malicious actors abusing this software.

Other Best Practice Mitigation Recommendations

• Use application allowlists on domain controllers, administrative hosts, and other sensitive systems. Following exploitation of the public-facing application (Zoho ManageEngine ServiceDesk Plus), APT actors were able to download and execute multiple files on the system, which were then utilized to enumerate the network and perform reconnaissance operations.
  • Use directory allowlisting rather than attempting to list every possible permutation of applications in a network environment. Safe defaults allow applications to run from PROGRAMFILES, PROGRAMFILES(X86), and SYSTEM32. Disallow all other locations unless an exception is granted and documented. Application directory allowlisting can be enabled through Microsoft Software Restriction Policy or AppLocker and can prevent the execution of unauthorized software.
• Audit scheduled tasks and validate all findings via a Group Policy Object (GPO) or endpoint detection and response (EDR) solution.
• Follow Microsoft’s Best Practices for Securing Active Directory.
• Review NSA’s Network Infrastructure Security Guide.

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA and co-sealers recommend 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 and co-sealers also recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

1. Select an ATT&CK technique described in this advisory (see Tables 3-13).
2. Align your security technologies against the technique.
3. Test your technologies against the technique.
4. Analyze your detection and prevention technologies performance.
5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

CISA and co-sealers 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

• NIST: NVD CVE-2022-47966
• NIST: NVD CVE-2022-42475
• CISA: KEV List
• MITRE ATT&CK for Enterprise v13.1
• CISA, MITRE: Best Practices for MITRE ATT&CK Mapping
• CISA: Decider Tool
• CISA: Cross-Sector Cybersecurity Performance Goals
• CISA: Cyber Hygiene Services
• CISA: Remediate Vulnerabilities for Internet-Accessible Systems
• CISA: Layering Network Security Through Segmentation
• NSA: Segment Networks and Deploy Application-Aware Defenses
• CISA: MFA
• CISA: Implementing Phishing-Resistant MFA
• Microsoft: Using Security Baselines in Your Organization
• CISA: Guide to Securing Remote Access Software
• Microsoft: Best Practices for Securing Active Directory
• NSA: Network Infrastructure Security Guide

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. CISA, the FBI, and CNMF 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, the FBI, or CNMF.

REFERENCES

1. Snort: Known Malicious User-Agent String – Mirai
2. MITRE: Mimikatz
3. MITRE: Ngrok
4. AA22-320A: Iranian Government-Sponsored APT Actors Compromise Federal Network, Deploy Crypto Miner, Credential Harvester
5. AA22-294A: #StopRansomware: Daixin Team
6. AA23-075A: #StopRansomware: LockBit 3.0
7. GitHub: Interactsh
8. Microsoft: Quser
9. Internet Engineering Task Force (IETF): RFC 9116

VERSION HISTORY

September 7, 2023: Initial version.