Trellix Insights: FoxSocket Backdoor Leverages WebSockets
Technical Articles ID:
KB95160
Last Modified: 2022-09-06 11:51:13 Etc/GMT
Last Modified: 2022-09-06 11:51:13 Etc/GMT
Environment
IMPORTANT: This Knowledge Base article discusses a specific threat that is being automatically tracked by Trellix Insights technology. The content is intended for use by Trellix Insights users, but is provided for general knowledge to all customers. Contact us for more information about Trellix Insights.
Summary
The operator behind PurpleFox added an additional vulnerability along with optimized rootkit capabilities to its arsenal. Also discovered was a .NET backdoor known as FoxSocket, which uses WebSockets to communicate with command-and-control (C&C) servers. Various WebSocket commands were sent from the server including system information and file and directory details. The attack campaign discovered targeted entities in the Middle East, and along with malware, used open-source components to carry out the infection process.
Our Threat Research team gathers and analyzes information from multiple open and closed sources before disseminating intelligence reports. This campaign was researched by Trend Micro and shared publicly.
How to use this article:
- If a Threat Hunting table has been created, use the rules contained to search for malware related to this campaign.
- Review the product detection table and confirm that your environment is at least on the specified content version.
To download the latest content versions, go to the Security Updates page. - Scroll down and review the "Product Countermeasures" section of this article. Consider implementing them if they are not already in place.
- Review
KB91836 - Countermeasures for entry vector threats . - Review KB87843 - Dynamic Application Containment rules and best practices.
- Review KB82925 - Identify what rule corresponds to an Adaptive Threat Protection and Threat Intelligence Exchange event.
Campaign IOC
Type | Value |
Minimum Content Versions
Content Type | Version |
Detection Summary
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
IOC | Scanner | Detection |
Minimum set of Manual Rules to improve protection to block this campaign:
IMPORTANT: Always follow best practices when you enable new rules and signatures.
When you implement new rules or signatures, always set them to Report mode first and check the alerts generated. Resolve any issues that arise and then set the rules to Block. This step mitigates against triggering false positives and allows you to refine your configuration.
For more information, see KB87843 - List of and best practices for Endpoint Security Dynamic Application Containment rules.
Endpoint Security - Advanced Threat Protection:
Host Intrusion Prevention:
Rule ID: 6135 Unmanaged PowerShell Detected
Rule ID: 6082 PowerShell Command Restriction - ExecutionPolicy Unrestricted
Rule ID: 6085 PowerShell Command Restriction - File
Aggressive set of Manual Rules to improve protection to block this campaign:
IMPORTANT: Always follow best practices when you enable new rules and signatures.
When you implement new rules or signatures, always set them to Report mode first and check the alerts generated. Resolve any issues that arise and then set the rules to Block. This step mitigates against triggering false positives and allows you to refine your configuration.
For more information, see KB87843 - List of and best practices for Endpoint Security Dynamic Application Containment rules.
VirusScan Enterprise - Access Protection Rules:
Host Intrusion Prevention:
Rule ID: 1020 Windows Agent Shielding - File Access
Rule ID: 990 New Startup Folder Program Creation
Rule ID: 6010 Generic Application Hooking Protection
Rule ID: 2265 Delay Delete File Protection
Rule ID: 6011 Generic Application Invocation Protection
Rule ID: 910 Uninstall Registry Key Modification
Rule ID: 2806 Attempt to create a hardlink to a file