yodasProtectorv101AshkbizDanehkar

Hunt Hypothesis

This YARA rule targets the YodasProtector malware variant, a low-severity threat often associated with specific obfuscation or protection mechanisms that may indicate early-stage compromise or targeted persistence. Proactively hunting for this signature in Azure Sentinel allows the SOC to identify hosts running this specific protector before it facilitates more advanced adversary actions, such as evading standard AV detection or establishing footholds in the environment.

YARA Rule

rule yodasProtectorv101AshkbizDanehkar
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 55 8B EC 53 56 57 E8 03 00 00 00 EB 01 ?? E8 86 00 00 00 E8 03 00 00 00 EB 01 ?? E8 79 00 00 00 E8 03 00 00 00 EB 01 ?? E8 A4 00 00 00 E8 03 00 00 00 EB 01 ?? E8 97 00 00 00 E8 03 00 00 00 EB 01 ?? E8 2D 00 00 00 E8 03 00 00 00 EB 01 ?? 60 E8 00 00 00 00 }

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: An IT administrator uses a legitimate, open-source YARA scanning utility (such as yarascan or a custom PowerShell wrapper) to perform a one-time audit of application binaries in the C:\Program Files directory to verify integrity. The tool loads the YARA rule file into memory and executes the scan, triggering the detection on the scanning process or the rule file itself.

  • Filter/Exclusion: Exclude processes where the parent process is a known administrative tool (e.g., powershell.exe, cmd.exe, or specific scanner executables like yara.exe) and the target file path resides in standard application directories (C:\Program Files, C:\Program Files (x86)). Additionally, exclude the YARA rule file if its path contains yodasProtectorv101AshkbizDanehkar and it is located in a designated “Rules” or “Signatures” folder.

• Scenario: A software development team uses a CI/CD pipeline agent (e.g., Jenkins, Azure DevOps, or GitHub Actions runner) to execute a build step that compiles or validates code using a YARA-based linter or security checker. The agent process loads the rule into memory during the build job, causing a false positive on the build service account.

  • Filter/Exclusion: Exclude processes running under the context of known CI/CD service accounts (e.g., jenkins, azuredevops, github-runner) or processes whose command line arguments contain keywords like build, lint, validate, or yara and are located in the CI/CD workspace directory (e.g., C:\workspace, C:\agent).

• Scenario: An endpoint detection and response (EDR) or antivirus solution (e.g., CrowdStrike, Defender for Endpoint, or SentinelOne) performs a