yodasProtectorv1033exescrcomAshkbizDanehkar

Hunt Hypothesis

This rule detects the execution of a specific malicious binary associated with the “yodasProtector” family, likely indicating a targeted intrusion or supply chain compromise. Proactively hunting for this signature in Azure Sentinel allows the SOC to identify compromised workstations or servers early, potentially preventing lateral movement or data exfiltration before the adversary establishes a persistent foothold.

YARA Rule

rule yodasProtectorv1033exescrcomAshkbizDanehkar
{
      meta:
		author="malware-lu"
strings:
		$a0 = { E8 03 00 00 00 EB 01 ?? BB 55 00 00 00 E8 03 00 00 00 EB 01 ?? E8 8E 00 00 00 E8 03 00 00 00 EB 01 ?? E8 81 00 00 00 E8 03 00 00 00 EB 01 ?? E8 B7 00 00 00 E8 03 00 00 00 EB 01 ?? E8 AA 00 00 00 E8 03 00 00 00 EB 01 ?? 83 FB 55 E8 03 00 00 00 EB 01 ?? 75 }

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

• Scenario: A developer or operations engineer manually compiles a C# or C++ application on a build server or developer workstation using the Microsoft Visual Studio Build Tools or csc.exe (C# Compiler) to generate a new executable file. The compiler process writes the resulting .exe file to disk, which matches the YARA signature for the yodasProtector packer/protector header.

  • Filter/Exclusion: Exclude alerts where the parent process is csc.exe, vbc.exe, cl.exe, or msbuild.exe, and the file path is located within a standard build output directory (e.g., bin\Debug, obj\Release, or a specific CI/CD workspace path).

• Scenario: An IT administrator uses a legitimate software installer or deployment tool (such as msiexec.exe or a custom PowerShell script using Expand-Archive followed by a copy operation) to deploy a third-party application that has been pre-protected with the yodasProtector packer for anti-tampering purposes. The extraction or copy process creates the protected executable on the target machine.

  • Filter/Exclusion: Exclude alerts where the parent process is msiexec.exe, powershell.exe (with a script path in a known admin tool directory), or cmd.exe executing a known deployment script, and the file is created in a standard application install directory (e.g., C:\Program Files\, C:\Program Files (x86)\).

• Scenario: A scheduled maintenance job or service (e.g., a custom .NET service or a Python script using pyinstaller or similar) regenerates or updates a small utility executable that has been packed with yodasProtector to protect its internal logic. This often happens during automated backup restoration or configuration sync tasks