mandiant/capa-rules

detect opening of services often referenced by ransomware

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#1,048 opened on May 22, 2025

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good first issuehelp wantedrule idea

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Description

Ransomware may attempt to open and stop specific services during execution, e.g. to stop critical backup and recovery services. The rule should include a list of target service names combined with Windows API calls, e.g. OpenService.

Example list: https://github.com/netskopeoss/NetskopeThreatLabsIOCs/blob/10b21b2fa5f280ea414fdbb47ea74c0386ab9587/Malware/BlackMatter/IOCs/README.md?plain=1#L58-L94

Contributor guide

Research direction
Review the capa rule format documentation. Use the provided list of service names. Write a rule that detects calls to OpenService or similar APIs with those service names. Test the rule against a ransomware sample that stops services.
Tech stack
python
Domain
security
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Windows APIcapa rules
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60