Trellix Insights: Fileless Malware Delivered Through Recent Phishing Campaign
Technical Articles ID:
KB96068
Last Modified: 2022-10-19 05:53:05 Etc/GMT
Last Modified: 2022-10-19 05:53:05 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
Description of Campaign
A spear-phishing campaign was discovered delivering three fileless malware intended to gather information and allow the threat actors to access the infected machines remotely. No attribution was given, but the malicious attachment and scripts used to retrieve and execute the malware were analyzed and reported on by Fortinet. The email delivered to the target contains an Excel document with hidden macros. Once opened, the target is presented with an enable macros notice. The attachment contains an auto-start macro that uses VBA code to obtain additional html files and set up tasks for persistence.
Our Threat Research team gathers and analyzes information from multiple open and closed sources before disseminating intelligence reports. This campaign was researched by Fortinet and shared publicly.
How to use this article:
Campaign IOC
Minimum Content Versions
Detection Summary
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:Rule ID: 259 Detect masqueraded files or process launches
Endpoint Security - Exploit Prevention:Rule ID: 6131 T1047 - Weaponized OLE object infection via WMI
Rule ID: 344 T1547 - New Startup Program Creation
Host Intrusion Prevention:Rule ID: 6085 PowerShell Command Restriction - File
Rule ID: 6096 PowerShell Command Restriction - InvokeExpression
Rule ID: 6135 Unmanaged PowerShell Detected
Rule ID: 6131 T1047 - Weaponized OLE object infection via WMI
Rule ID: 6113 T1055 - Fileless Threat: Reflective Self Injection
Rule ID: 6083 PowerShell Command Restriction - NonInteractive
Rule ID: 6070 Hidden PowerShell Detected
Rule ID: 6081 PowerShell Command Restriction - NoProfile
Rule ID: 6082 PowerShell Command Restriction - ExecutionPolicy Unrestricted
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 programs registering to autorun
Prevent creation of new executable files in the Windows folder
Host Intrusion Prevention:Rule ID: 6011 Generic Application Invocation Protection
Rule ID: 1020 Windows Agent Shielding - File Access
Rule ID: 6010 Generic Application Hooking Protection
Rule ID: 344 T1547 - New Startup Program Creation
Rule ID: 1148 CMD Tool Access by a Network Aware Application
A spear-phishing campaign was discovered delivering three fileless malware intended to gather information and allow the threat actors to access the infected machines remotely. No attribution was given, but the malicious attachment and scripts used to retrieve and execute the malware were analyzed and reported on by Fortinet. The email delivered to the target contains an Excel document with hidden macros. Once opened, the target is presented with an enable macros notice. The attachment contains an auto-start macro that uses VBA code to obtain additional html files and set up tasks for persistence.
Our Threat Research team gathers and analyzes information from multiple open and closed sources before disseminating intelligence reports. This campaign was researched by Fortinet 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 |
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:
Endpoint Security - Exploit Prevention:
Rule ID: 344 T1547 - New Startup Program Creation
Host Intrusion Prevention:
Rule ID: 6096 PowerShell Command Restriction - InvokeExpression
Rule ID: 6135 Unmanaged PowerShell Detected
Rule ID: 6131 T1047 - Weaponized OLE object infection via WMI
Rule ID: 6113 T1055 - Fileless Threat: Reflective Self Injection
Rule ID: 6083 PowerShell Command Restriction - NonInteractive
Rule ID: 6070 Hidden PowerShell Detected
Rule ID: 6081 PowerShell Command Restriction - NoProfile
Rule ID: 6082 PowerShell Command Restriction - ExecutionPolicy Unrestricted
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: 1020 Windows Agent Shielding - File Access
Rule ID: 6010 Generic Application Hooking Protection
Rule ID: 344 T1547 - New Startup Program Creation
Rule ID: 1148 CMD Tool Access by a Network Aware Application