EXECryptor2117StrongbitSoftCompleteDevelopment

Hunt Hypothesis

This rule detects the presence of the StrongbitSoft Complete Development executable, a component frequently leveraged by adversaries for persistence or process injection within Windows environments. Proactively hunting for this artifact in Azure Sentinel allows the SOC to identify low-severity footholds or supply chain compromises that may precede more advanced post-exploitation activities.

YARA Rule

rule EXECryptor2117StrongbitSoftCompleteDevelopment
{
      meta:
		author="malware-lu"
strings:
		$a0 = { BE [4] B8 00 00 [2] 89 45 FC 89 C2 8B 46 0C 09 C0 0F 84 ?? 00 00 00 01 D0 89 C3 50 FF 15 94 [3] 09 C0 0F 85 0F 00 00 00 53 FF 15 98 [3] 09 C0 0F 84 ?? 00 00 00 89 45 F8 6A 00 8F 45 F4 8B 06 09 C0 8B 55 FC 0F 85 03 00 00 00 8B 46 10 01 }

condition:
		$a0
}

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 build engineer runs the StrongbitSoft complete development suite (e.g., sbdev.exe or strongbit-compiler.exe) locally to compile proprietary modules. The executable is digitally signed by StrongbitSoft and resides in a standard development directory like C:\Dev\StrongbitSoft\bin\.

  • Filter/Exclusion: Exclude processes where the parent process is a known IDE (e.g., devenv.exe, code.exe, idea64.exe) or where the image path matches C:\Dev\StrongbitSoft\bin\*.exe and the file is signed by “StrongbitSoft”.

• Scenario: An automated CI/CD pipeline agent (e.g., Azure DevOps Agent or Jenkins Node) executes the StrongbitSoft development tools as part of a scheduled build job. The process runs under a service account (e.g., svc-ci-build) and is launched by the agent’s worker process.

  • Filter/Exclusion: Exclude events where the parent process name is vstsagent.exe, jenkins.exe, or agent.exe, and the user account matches the CI/CD service account pattern (e.g., svc-ci-*).

• Scenario: A QA engineer performs manual regression testing using the StrongbitSoft development environment to generate test reports or debug binaries. The tool is invoked via a shortcut or script from a user’s home directory or a shared test folder (\\fileserver\qa\tools\).

  • Filter/Exclusion: Exclude processes where the image path contains \qa\tools\ or \test\ in the directory structure, and the user is a member of the QA-Engineers security group.

• Scenario: A system administrator runs the StrongbitSoft development utility as part of a one-off maintenance task to update internal libraries