Threat Update: Hidden Cobra – Volgmer Trojan
Herjavec Group continues to closely monitor the news and activity around Hidden Cobra.
Managed Security Services customers can rest assured that should there be an escalation in your environment related to Hidden Cobra, the alert shared with you via HG’s Analytics Platform will be enriched with threat intelligence to indicate the applicable Threat Actors. The static and dynamic IPs outlined in the recent US cert advisory are updated in real time within the Herjavec Group Analytics Platform through our multi-tiered threat intelligence program which includes Anomali integration.
The Technical Alert below was initially published by the Department of Homeland Security and the FBI.
The US Government refers to malicious activity by the North Korean government as Hidden Cobra.
For more information on HIDDEN COBRA activity, please click here.
FBI has high confidence that HIDDEN COBRA actors are using the IP addresses—listed in this report’s IOC files—to maintain a presence on victims’ networks and to further network exploitation. DHS and FBI are distributing these IP addresses to enable network defense and reduce exposure to North Korean government malicious cyber activity.
This alert includes IOCs related to HIDDEN COBRA, IP addresses linked to systems infected with Volgmer malware, malware descriptions, and associated signatures. This alert also includes suggested response actions to the IOCs provided, recommended mitigation techniques, and information on reporting incidents. If users or administrators detect activity associated with the Volgmer malware, they should immediately flag it, report it to the DHS National Cybersecurity and Communications Integration Center (NCCIC) or the FBI Cyber Watch (CyWatch), and give it the highest priority for enhanced mitigation.
For a downloadable copy of IOCs, see:
NCCIC conducted analysis on five files associated with or identified as Volgmer malware and produced a Malware Analysis Report (MAR). MAR-10135536-D examines the tactics, techniques, and procedures observed.
For a downloadable copy of the MAR, see:
What Is Volgmer?
Volgmer is a backdoor Trojan designed to provide covert access to a compromised system. Since at least 2013, HIDDEN COBRA actors have been observed using Volgmer malware in the wild to target the government, financial, automotive, and media industries.
It is suspected that spear phishing is the primary delivery mechanism for Volgmer infections; however, HIDDEN COBRA actors use a suite of custom tools, some of which could also be used to initially compromise a system. Therefore, it is possible that additional HIDDEN COBRA malware may be present on network infrastructure compromised with Volgmer
The U.S. Government has analyzed Volgmer’s infrastructure and have identified it on systems using both dynamic and static IP addresses. At least 94 static IP addresses were identified, as well as dynamic IP addresses registered across various countries. The greatest concentrations of dynamic IPs addresses are identified below by approximate percentage:
- India (772 IPs) 25.4 percent
- Iran (373 IPs) 12.3 percent
- Pakistan (343 IPs) 11.3 percent
- Saudi Arabia (182 IPs) 6 percent
- Taiwan (169 IPs) 5.6 percent
- Thailand (140 IPs) 4.6 percent
- Sri Lanka (121 IPs) 4 percent
- China (82 IPs, including Hong Kong (12)) 2.7 percent
- Vietnam (80 IPs) 2.6 percent
- Indonesia (68 IPs) 2.2 percent
- Russia (68 IPs) 2.2 percent
As a backdoor Trojan, Volgmer has several capabilities including: gathering system information, updating service registry keys, downloading and uploading files, executing commands, terminating processes, and listing directories. In one of the samples received for analysis, the US-CERT Code Analysis Team observed botnet controller functionality.
Volgmer payloads have been observed in 32-bit form as either executables or dynamic-link library (.dll) files. The malware uses a custom binary protocol to beacon back to the command and control (C2) server, often via TCP port 8080 or 8088, with some payloads implementing Secure Socket Layer (SSL) encryption to obfuscate communications.
Malicious actors commonly maintain persistence on a victim’s system by installing the malware-as-a-service. Volgmer queries the system and randomly selects a service in which to install a copy of itself. The malware then overwrites the ServiceDLL entry in the selected service’s registry entry. In some cases, HIDDEN COBRA actors give the created service a pseudo-random name that may be composed of various hardcoded words.
Detection and Response
This alert’s IOC files provide HIDDEN COBRA indicators related to Volgmer. DHS and FBI recommend that network administrators review the information provided, identify whether any of the provided IP addresses fall within their organizations’ allocated IP address space, and—if found—take necessary measures to remove the malware.
When reviewing network perimeter logs for the IP addresses, organizations may find instances of these IP addresses attempting to connect to their systems. Upon reviewing the traffic from these IP addresses, system owners may find some traffic relates to malicious activity and some traffic relates to legitimate activity.
Network Signatures and Host-Based Rules
This section contains network signatures and host-based rules that can be used to detect malicious activity associated with HIDDEN COBRA actors. Although created using a comprehensive vetting process, the possibility of false positives always remains. These signatures and rules should be used to supplement analysis and should not be used as a sole source of attributing this activity to HIDDEN COBRA actors.
alert tcp any any -> any any (msg:”Malformed_UA”; content:”User-Agent: Mozillar/”; depth:500; sid:99999999;)
A successful network intrusion can have severe impacts, particularly if the compromise becomes public and sensitive information is exposed. Possible impacts include:
- temporary or permanent loss of sensitive or proprietary information,
- disruption to regular operations,
- financial losses incurred to restore systems and files, and
- potential harm to an organization’s reputation.
HG supports the DHS recommendation that users and administrators use the following best practices as preventive measures to protect their computer networks:
- Use application whitelisting to help prevent malicious software and unapproved programs from running. Application whitelisting is one of the best security strategies as it allows only specified programs to run while blocking all others, including malicious software.
- Keep operating systems and software up-to-date with the latest patches. Vulnerable applications and operating systems are the targets of most attacks. Patching with the latest updates greatly reduces the number of exploitable entry points available to an attacker.
- Maintain up-to-date antivirus software, and scan all software downloaded from the Internet before executing.
- Restrict users’ abilities (permissions) to install and run unwanted software applications, and apply the principle of “least privilege” to all systems and services. Restricting these privileges may prevent malware from running or limit its capability to spread through the network.
- Avoid enabling macros from email attachments. If a user opens the attachment and enables macros, embedded code will execute the malware on the machine. For enterprises or organizations, it may be best to block email messages with attachments from suspicious sources.
- Do not follow unsolicited web links in emails.
Herjavec Group circulates US – CERT advisories as this notification warrants attention and may have significance to your Enterprise network environment. If the following advisory is applicable to your environment, Herjavec Group recommends your IT team review the technical details included and monitor your environment for any susceptible systems. Herjavec Group’s analysts are working with applicable vendor partners to apply detection and mitigation strategies where appropriate. For Managed Services customers, our Managed Services team will engage with the appropriate technical contacts in your respective organizations directly to provide alerts, escalations, actions and or reports based our service agreement with you. If you have questions or concerns, please engage your Herjavec Group account representative directly or contact Herjavec Group.
About Herjavec Group
Dynamic IT entrepreneur Robert Herjavec founded Herjavec Group in 2003 to provide cybersecurity products and services to enterprise organizations. Herjavec Group delivers SOC 2 Type 2 certified managed security services supported by state-of-the-art, PCI compliant, Security Operations Centers, operated 24/7/365 by certified security professionals. This expertise is coupled with leadership positions across a wide range of functions including consulting, professional services & incident response. Herjavec Group has offices globally including across the United States, the United Kingdom, and Canada. For more information, visit www.herjavecgroup.com.