Russian State-Sponsored Espionage Group Static Tundra Compromises Unpatched End-Of-Life Network Devi
Summary:
Since at least 2015, a Russian state-sponsored cyber espionage group, named Static Tundra, has been targeting unpatched and end-of-life Cisco networking devices. Cisco Talos assesses with high confidence that the group is a sub-cluster of the notorious Energetic Bear (aka BERSERK BEAR) group, with ties to the Russian Federal Security Service (FSB). Static Tundra is highly sophisticated and has demonstrated advanced knowledge of network devices, using bespoke tools to conduct long-term intelligence gathering operations post-compromise. The group primarily targets the telecommunications, higher education, and manufacturing sectors across North America, Asia, Africa, and Europe, with a specific focus on Ukraine, its allies, and the strategic interests of the Russian government. Its main objective is to compromise devices to extract configuration information and establish persistent access for long-term intelligence gathering, a strategy that has allowed the group to remain undetected for years.
Static Tundra’s primary method of initial access involves exploiting a known vulnerability (CVE-2018-0171) in the Smart Install feature of Cisco IOS software, which was patched in 2018 but is often left unpatched on older devices, according to Talos. After gaining access, the group enables a local TFTP server to exfiltrate the device's startup configuration, which can contain sensitive credentials and community strings. Alternatively, they gain initial access via compromised or insecure SNMP community strings, such as “anonymous” and “public.” For persistence, the group creates new user accounts, modifies SNMP community strings, and uses a modular firmware implant called SYNful Knock, which can survive device reboots. To evade detection, Static Tundra modifies TACACS+ configurations to disable remote logging and alters access control lists (ACLs) to permit their own IP addresses. For collection and exfiltration, they establish Generic Routing Encapsulation (GRE) tunnels to redirect traffic to their infrastructure and use various methods, including TFTP and FTP, to steal configuration files.
Security Officer Comments:
The recently observed activities of Static Tundra reinforce the sophisticated and state-sponsored nature of their operations. The group’s focus on unpatched, often end-of-life, network devices demonstrates a strategic understanding of common security failures within organizations. Utilizing this understanding in conjunction with well-resourced reconnaissance allows the threat actor to more conducively breach high-value targets. This reliance on a known, several-year-old vulnerability (CVE-2018-0171) for initial access underscores the critical importance of timely, organized patch management and device lifecycle monitoring. The use of insecure, default SNMP strings and the creation of custom tooling like SYNful Knock reveal a methodical approach to maintaining long-term access. These two factors underscore the lengthy history of this actor, with Talos assessing with moderate confidence that Static Tundra was involved in the compromise of Cisco devices via SYNful Knock in 2015. Organizations should not only focus on patching but also on re-evaluating their security posture for all network infrastructure, especially older devices that are past their end-of-life, as they present a high-value target for persistent threat actors like Static Tundra and likely others. Talos notes that network devices afford state-sponsored adversaries coveted access, and organizations should prioritize proactively defending these devices.
Suggested Corrections:
IOCs are available here.
Talos recommends taking the following steps to identify suspicious activity that may be related to this campaign:
Cisco-specific measures
https://blog.talosintelligence.com/static-tundra/
Since at least 2015, a Russian state-sponsored cyber espionage group, named Static Tundra, has been targeting unpatched and end-of-life Cisco networking devices. Cisco Talos assesses with high confidence that the group is a sub-cluster of the notorious Energetic Bear (aka BERSERK BEAR) group, with ties to the Russian Federal Security Service (FSB). Static Tundra is highly sophisticated and has demonstrated advanced knowledge of network devices, using bespoke tools to conduct long-term intelligence gathering operations post-compromise. The group primarily targets the telecommunications, higher education, and manufacturing sectors across North America, Asia, Africa, and Europe, with a specific focus on Ukraine, its allies, and the strategic interests of the Russian government. Its main objective is to compromise devices to extract configuration information and establish persistent access for long-term intelligence gathering, a strategy that has allowed the group to remain undetected for years.
Static Tundra’s primary method of initial access involves exploiting a known vulnerability (CVE-2018-0171) in the Smart Install feature of Cisco IOS software, which was patched in 2018 but is often left unpatched on older devices, according to Talos. After gaining access, the group enables a local TFTP server to exfiltrate the device's startup configuration, which can contain sensitive credentials and community strings. Alternatively, they gain initial access via compromised or insecure SNMP community strings, such as “anonymous” and “public.” For persistence, the group creates new user accounts, modifies SNMP community strings, and uses a modular firmware implant called SYNful Knock, which can survive device reboots. To evade detection, Static Tundra modifies TACACS+ configurations to disable remote logging and alters access control lists (ACLs) to permit their own IP addresses. For collection and exfiltration, they establish Generic Routing Encapsulation (GRE) tunnels to redirect traffic to their infrastructure and use various methods, including TFTP and FTP, to steal configuration files.
Security Officer Comments:
The recently observed activities of Static Tundra reinforce the sophisticated and state-sponsored nature of their operations. The group’s focus on unpatched, often end-of-life, network devices demonstrates a strategic understanding of common security failures within organizations. Utilizing this understanding in conjunction with well-resourced reconnaissance allows the threat actor to more conducively breach high-value targets. This reliance on a known, several-year-old vulnerability (CVE-2018-0171) for initial access underscores the critical importance of timely, organized patch management and device lifecycle monitoring. The use of insecure, default SNMP strings and the creation of custom tooling like SYNful Knock reveal a methodical approach to maintaining long-term access. These two factors underscore the lengthy history of this actor, with Talos assessing with moderate confidence that Static Tundra was involved in the compromise of Cisco devices via SYNful Knock in 2015. Organizations should not only focus on patching but also on re-evaluating their security posture for all network infrastructure, especially older devices that are past their end-of-life, as they present a high-value target for persistent threat actors like Static Tundra and likely others. Talos notes that network devices afford state-sponsored adversaries coveted access, and organizations should prioritize proactively defending these devices.
Suggested Corrections:
IOCs are available here.
Talos recommends taking the following steps to identify suspicious activity that may be related to this campaign:
- Conduct comprehensive configuration management (including auditing), in line with best practices.
- Conduct comprehensive authentication, authorization and command issuance monitoring.
- Monitor syslog and AAA logs for unusual activity, including a decrease in normal logging events, or a gap in logged activity.
- Monitor your environment for unusual changes in behavior or configuration.
- Profile (fingerprint via NetFlow and port scanning) network devices for a shift in surface view, including new ports opening/closing and traffic to/from (not traversing).
- Where possible, develop NetFlow visibility to identify unusual volumetric changes.
- Look for non-empty or unusually large .bash_history files.
Cisco-specific measures
- Apply the patch for CVE-2018-0171.
- Disable Smart Install as indicated in the advisory if patching is not an option.
- Leverage Cisco Hardening Guides when configuring devices.
- Disable telnet and ensure it is not available on any of the Virtual Teletype (VTY) lines on Cisco devices by configuring all VTY stanzas with “transport input ssh” and “transport output none”.
- Disable Cisco’s Smart Install service using “no vstack” for any device where application of the available patch for CVE 2018-0171 is infeasible, and develop end-of-life management plans for technology too old to patch.
- Utilize Type 8 passwords for local account credential configuration.
- Utilize Type 6 for TACACS+ key configuration.
- Rigorously adhere to security best practices, including updating, access controls, user education and network segmentation.
- Stay up to date on security advisories from the U.S. government and industry and consider suggested configuration changes to mitigate described issues.
- Update devices as aggressively as possible. This includes patching current hardware and software against known vulnerabilities and replacing end-of- life hardware and software.
- Select complex passwords and community strings and avoid default credentials.
- Use multi-factor authentication (MFA).
- Encrypt all monitoring and configuration traffic (e.g., SNMPv3, HTTPS, SSH, NETCONF, RESTCONF).
- Lock down and aggressively monitor credential systems, such as TACACS+ and any jump hosts.
- Utilize AAA to deny configuration modifications of key device protections (e.g., local accounts, TACACS+, RADIUS).
- Prevent and monitor for exposure of administrative or unusual interfaces (e.g., SNMP, SSH, HTTP, HTTPS).
- Disable all non-encrypted web management capabilities.
- Verify existence and correctness of access control lists for all management protocols (e.g., SNMP, SSH, Netconf, etc.).
- Store configurations centrally and push to devices. Do NOT allow devices to be the trusted source of truth for their configurations.
https://blog.talosintelligence.com/static-tundra/