FANCY BEAR GONEPOSTAL – Espionage Tool Provides Backdoor Access to Microsoft Outlook
Summary:
A recent espionage campaign attributed to the Russian state-sponsored group KTA007 (also known as Fancy Bear or APT28) has been identified by Kroll and is utilizing a new malware named GONEPOSTAL. The malware is delivered via a malicious DLL file, which uses DLL side-loading to disguise itself as a legitimate Microsoft file. This DLL executes hidden PowerShell commands to deploy a file, VbaProject.OTM, which is crucial for backdoor activation, into the user's Outlook profile directory. By modifying Windows Registry keys, the malware forces Outlook to load this malicious file, effectively creating a backdoor that operates through Outlook's built-in VBA macro engine.
Once Outlook is launched, GONEPOSTAL activates, turning the email client into a covert C2 channel. The malware monitors incoming emails for specific, encoded instructions from the attackers. When a C2 email is detected, the malware parses the command, executes it (which can include remote file operations, PowerShell execution, and data exfiltration), and then self-cleans by deleting the email from the inbox and deleted folders. Data is exfiltrated and sent back to the adversary as legitimate-looking email attachments, a method that makes it extremely difficult to detect, as it blends in with normal email traffic.
Security Officer Comments:
This sophisticated "living off the land" C2 channel technique, accomplished by abusing Outlook, highlights the group's advanced capabilities and focus on long-term espionage in enterprise environments. The GONEPOSTAL campaign is a useful example of a highly persistent and stealthy APT actor evolving their tactics to better avoid detection. APT28's choice to repurpose Microsoft Outlook as a C2 channel is highly effective. By "living off the land," the group makes the more traditional network and endpoint security measures less effective for detecting its operations, as its malicious access is camouflaged within legitimate enterprise email traffic. This campaign underscores the importance of organizations to prioritize spending towards not only blocking known threats, but also monitoring for abnormal behaviors within trusted applications. The ingenuity of this attack, like its use of DLL side-loading and registry key modification to bypass security alerts, further solidifies APT28's historical reputation as a capable state-sponsored cyber espionage group.
Suggested Corrections:
Organizations can make APT groups’ lives more difficult. Here’s how:
https://www.kroll.com/en/publications/cyber/fancy-bear-gonepostal-espionage-tool-backdoor-access-microsoft-outlook
A recent espionage campaign attributed to the Russian state-sponsored group KTA007 (also known as Fancy Bear or APT28) has been identified by Kroll and is utilizing a new malware named GONEPOSTAL. The malware is delivered via a malicious DLL file, which uses DLL side-loading to disguise itself as a legitimate Microsoft file. This DLL executes hidden PowerShell commands to deploy a file, VbaProject.OTM, which is crucial for backdoor activation, into the user's Outlook profile directory. By modifying Windows Registry keys, the malware forces Outlook to load this malicious file, effectively creating a backdoor that operates through Outlook's built-in VBA macro engine.
Once Outlook is launched, GONEPOSTAL activates, turning the email client into a covert C2 channel. The malware monitors incoming emails for specific, encoded instructions from the attackers. When a C2 email is detected, the malware parses the command, executes it (which can include remote file operations, PowerShell execution, and data exfiltration), and then self-cleans by deleting the email from the inbox and deleted folders. Data is exfiltrated and sent back to the adversary as legitimate-looking email attachments, a method that makes it extremely difficult to detect, as it blends in with normal email traffic.
Security Officer Comments:
This sophisticated "living off the land" C2 channel technique, accomplished by abusing Outlook, highlights the group's advanced capabilities and focus on long-term espionage in enterprise environments. The GONEPOSTAL campaign is a useful example of a highly persistent and stealthy APT actor evolving their tactics to better avoid detection. APT28's choice to repurpose Microsoft Outlook as a C2 channel is highly effective. By "living off the land," the group makes the more traditional network and endpoint security measures less effective for detecting its operations, as its malicious access is camouflaged within legitimate enterprise email traffic. This campaign underscores the importance of organizations to prioritize spending towards not only blocking known threats, but also monitoring for abnormal behaviors within trusted applications. The ingenuity of this attack, like its use of DLL side-loading and registry key modification to bypass security alerts, further solidifies APT28's historical reputation as a capable state-sponsored cyber espionage group.
Suggested Corrections:
Organizations can make APT groups’ lives more difficult. Here’s how:
- Defense-in-depth strategy: A comprehensive defense-in-depth strategy is crucial to combat APTs. This includes implementing multiple layers of security controls, such as strong perimeter defenses, network segmentation, endpoint protection, intrusion detection systems, data encryption, access controls, and continuous monitoring for anomalies.
- Threat intelligence and sharing: Ideally, organizations should actively participate in threat intelligence sharing communities and collaborate with industry peers, government agencies, and security vendors. Sharing information about APTs and their techniques can help detect and mitigate attacks more effectively.
- Employee education and awareness: Regular security awareness programs, phishing simulations, and training sessions can educate employees about the latest threats, social engineering techniques, and safe computing practices.
- Incident response and recovery: Regardless of preventive measures, organizations should have a well-defined incident response plan. This includes incident detection, containment, eradication, and recovery procedures to minimize the impact of APT attacks and restore normal operations.
https://www.kroll.com/en/publications/cyber/fancy-bear-gonepostal-espionage-tool-backdoor-access-microsoft-outlook