Trellix Insights: FIN7 using themed docs to drop JavaScript backdoor
Technical Articles ID:
KB95184
Last Modified: 2022-09-06 04:41:18 Etc/GMT
Last Modified: 2022-09-06 04:41:18 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 FIN7 threat group used malicious Microsoft Windows 11 Alpha-themed Word documents with Visual Basic macros to drop JavaScript payloads. The campaign started with a Word document that contained a decoy image, which required the victim to Enable Editing and Enable Content to carry the infection process. If a certain language or Virtual Machines were detected on the infected system, the malicious code would not proceed to the next step.
Our Threat Research team gathers and analyzes information from multiple open and closed sources before disseminating intelligence reports. This campaign was researched by Anomali 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.
meta: description = "Detects suspicious string that asks to enable active content in Office Doc" author = "Florian Roth" reference = "Internal Research" date = "2019-02-12" hash1 = "525ba2c8d35f6972ac8fcec8081ae35f6fe8119500be20a4113900fe57d6a0de" strings: $e1 = "Enable Editing" fullword ascii $e2 = "Enable Content" fullword ascii $e3 = "Enable editing" fullword ascii $e4 = "Enable content" fullword ascii condition: uint16(0) == 0xcfd0 and ( $e1 in (0..3000) or $e2 in (0..3000) or $e3 in (0..3000) or $e4 in (0..3000) or 2 of them ) } |
This Knowledge Base article discusses a specific threat that's being tracked. The list of IOCs will change over time; check Trellix Insights for the latest IOCs.
Campaign IOC
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Minimum Content Versions
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Detection Summary
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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 - Exploit Prevention:
Host Intrusion Prevention:
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:
Prevent creation of new executable files in the Windows folder
Host Intrusion Prevention:
Rule ID: 1148 CMD Tool Access by a Network Aware Application
Rule ID: 6011 Generic Application Invocation Protection
Rule ID: 1020 Windows Agent Shielding - File Access
Rule ID: 2806 Attempt to create a hardlink to a file
