ASProtectv12xNewStrain

Hunt Hypothesis

This hunt hypothesis targets adversaries deploying a new strain of malware protected by the ASProtect v12.x packing engine to evade traditional signature-based detection. Proactively hunting for this behavior in Azure Sentinel is critical because its current low severity rating may cause it to be overlooked, allowing stealthy initial access and lateral movement before higher-severity alerts trigger.

YARA Rule

rule ASProtectv12xNewStrain
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 68 01 [3] E8 01 [3] C3 C3 }

condition:
		$a0 at pe.entry_point
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

• Microsoft Defender for Endpoint — Custom indicators / advanced hunting
• Email Gateway — Attachment scanning
• File Share Monitoring — Periodic scanning of shared drives
• YARA CLI — Manual threat hunting on endpoints

This rule contains 1 string patterns in its detection logic.

• Source Rule

False Positive Guidance

Here are 4 specific false positive scenarios for the ASProtectv12xNewStrain detection rule, including suggested filters and exclusions:

• Scenario: Deployment of AS-Protected Enterprise License Keys via SCCM

  • Context: The IT team uses Microsoft Endpoint Configuration Manager (SCCM) to push a new batch of license keys for the “AcmeCorp CRM” application. Since this application is wrapped in ASProtect v12.x, the deployment agent triggers the YARA rule as it extracts and executes the protected installer on 50+ workstations simultaneously.
  • Filter/Exclusion: Create a whitelist exclusion based on the SCCM client process (ccmsetup.exe or WUAHandler.exe) executing within the C:\Program Files\Microsoft Configuration Manager\AdminConsole\ directory, or exclude file paths containing \AcmeCorp CRM\Installers\.

• Scenario: Scheduled Backup of AS-Protected Legacy Financial Reports

  • Context: A nightly scheduled job runs using Veeam Backup & Replication to archive the “Q3 Financial Audit” folder. This folder contains legacy reports generated by a tool wrapped in ASProtect v12.x. The backup agent scans and reads these protected binaries, causing the YARA rule to flag them as new strains due to the file access pattern during the scan window (02:00 – 04:00 AM).
  • Filter/Exclusion: Implement a time-based exclusion for the Veeam backup service process (Veeam.Backup.Service.exe) specifically between 01:30 and 05:00 on weekdays, or exclude any file path matching D:\Backups\FinancialReports\*.

• Scenario: Automated Patching of Third-Party Security Plugins

  • Context: The automated patch management tool (e.g