AnskyaBinderv11Anskya

Hunt Hypothesis

This detection targets adversaries utilizing the specific Anskya binder variant to stage or execute malicious payloads within the environment. Proactive hunting for this signature in Azure Sentinel is essential to identify early-stage infection vectors that may evade standard heuristic controls due to their low-severity classification.

YARA Rule

rule AnskyaBinderv11Anskya
{
      meta:
		author="malware-lu"
strings:
		$a0 = { BE [3] 00 BB F8 11 40 00 33 ED 83 EE 04 39 2E 74 11 }

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 5 specific false positive scenarios for the AnskyaBinderv11Anskya YARA rule, along with suggested filters and exclusions tailored for an enterprise environment:

• Scenario: Execution of legitimate software installers (e.g., Microsoft Office, Adobe Creative Cloud) that utilize the Anskya binder to package multiple components into a single executable.

  • Suggested Filter/Exclusion: Exclude processes where the ImageName matches known installer paths (e.g., C:\Program Files\Microsoft Office\Setup.exe, C:\Program Files\Adobe\Installers\...) and the ParentProcessName is a recognized deployment tool like msiexec.exe or wixburn.exe.

• Scenario: Scheduled maintenance jobs running during off-hours that utilize custom scripts wrapped in an Anskya-bundled utility for patch management (e.g., SCCM/MECM client updates).

  • Suggested Filter/Exclusion: Create a time-based exclusion allowing the rule to remain inactive between 02:00 and 05:00 local time, or specifically exclude processes launched by Task Scheduler (svchost.exe -k netsvcs) where the command line contains keywords like “Patch” or “Update”.

• Scenario: Legitimate internal development tools (e.g., CI/CD agents running Jenkins or GitLab Runners) that bundle build artifacts using the Anskya framework for deployment to edge servers.

  • Suggested Filter/Exclusion: Whitelist processes originating from specific service accounts (e.g., DOMAIN\svc-build-agent) and restrict detection to exclude file paths within designated development directories such as C:\Jenkins\workspace or D:\GitLabRunners.

• Scenario: Execution of third-party endpoint protection agents (e.g., CrowdStrike, Carbon Black