AI1Creator1Beta2byMZ

Hunt Hypothesis

This rule detects the presence of the AI1Creator1Beta2byMZ malware variant, which may indicate an initial foothold or a targeted deployment of a low-severity threat actor. Proactively hunting for this signature allows the SOC team to identify compromised endpoints early and investigate potential lateral movement or data staging activities before the adversary escalates their operations.

YARA Rule

rule AI1Creator1Beta2byMZ
{
      meta:
		author="malware-lu"
strings:
		$a0 = { E8 FE FD FF FF 6A 00 E8 0D 00 00 00 CC FF 25 78 10 40 00 FF 25 7C 10 40 00 FF 25 80 10 40 00 FF 25 84 10 40 00 FF 25 88 10 40 00 FF 25 8C 10 40 00 FF 25 90 10 40 00 FF 25 94 10 40 00 FF 25 98 10 40 00 FF 25 9C 10 40 00 FF 25 A0 10 40 00 FF 25 A4 10 40 00 FF 25 AC 10 40 00 }

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 DevOps engineer is actively compiling and testing the AI1Creator1 application (specifically the Beta 2 build) on a build server or developer workstation. The YARA rule matches the specific binary structure or string patterns of this legitimate, in-house or third-party AI tooling suite.

  • Filter/Exclusion: Exclude processes where the executable path matches C:\Projects\AI1Creator\bin\AI1Creator1Beta2.exe or C:\Builds\AI1Creator\AI1Creator1Beta2.exe. Additionally, exclude if the parent process is a known IDE (e.g., devenv.exe, code.exe) or a build tool (e.g., msbuild.exe, dotnet.exe).

• Scenario: An automated scheduled task or CI/CD pipeline job runs a post-build verification script that launches AI1Creator1Beta2 to generate metadata or perform unit tests. The rule triggers because the binary is executed in a service context or by a task scheduler agent.

  • Filter/Exclusion: Exclude if the parent process is Task Scheduler (svchost.exe with specific service arguments) or cmd.exe/powershell.exe launched by a CI agent (e.g., agent.exe, runner.exe). Verify the working directory is within a known CI/CD workspace path (e.g., C:\agent\_work\).

• Scenario: A security analyst or tester is performing a manual validation or regression test of the detection rule itself in a sandboxed environment or on a dedicated test machine. The rule triggers because the known good sample AI1Creator1Beta2 is intentionally executed.

  • Filter/Exclusion: Exclude if the machine is tagged as “Test Environment” or “Sandbox” in your CMDB or asset inventory. Alternatively,