🛡️ Cyber Defense & SOC · Detection & Purple Team

Engineer detections through a full lifecycle (Microsoft Sentinel)

Ship detection rules like code: versioned, tested, tuned, and retired deliberately.

advanced~40 minSOC AnalystsDetection EngineersThreat Hunters

Steps

1Draft rule from hunt/intel with explicit logic rationale documented
2Backtest against 30 days of data; measure raw hit volume
3Tune out benign-true noise using environment baselines, not blanket exclusions
4Stage: silent-run in prod for one week comparing predicted vs actual hits
5Enable with severity matched to expected fidelity; document false-positive budget
6Review rule precision quarterly; retire or rewrite below threshold
7Deploy analytics rules as code via ARM/Bicep pipelines
8Watch ingestion latency when setting query frequency

Common Pitfalls

▲Rules enabled then never revisited until they page falsely
▲Exclusions so broad they hollow out the logic

Commands

Install with skills CLI

$ npx skills add aniruddhaadak80/skills --skill detection-purple-detection-rule-lifecycle-sentinel

Install globally

$ npx skills add aniruddhaadak80/skills --skill detection-purple-detection-rule-lifecycle-sentinel -g

Tags

#detection-engineering#as-code#cyber-defense-ops#detection-purple

Install this skill

$ npx skills add aniruddhaadak80/skills --skill detection-purple-detection-rule-lifecycle-sentinel -a opencode

SKILL.md

# Engineer detections through a full lifecycle (Microsoft Sentinel)

> Ship detection rules like code: versioned, tested, tuned, and retired deliberately.

## When to Use This Skill

Ship detection rules like code: versioned, tested, tuned, and retired deliberately.

## Steps

1. Draft rule from hunt/intel with explicit logic rationale documented
2. Backtest against 30 days of data; measure raw hit volume
3. Tune out benign-true noise using environment baselines, not blanket exclusions
4. Stage: silent-run in prod for one week comparing predicted vs actual hits
5. Enable with severity matched to expected fidelity; document false-positive budget
6. Review rule precision quarterly; retire or rewrite below threshold
7. Deploy analytics rules as code via ARM/Bicep pipelines
8. Watch ingestion latency when setting query frequency

## Common Pitfalls

- Rules enabled then never revisited until they page falsely
- Exclusions so broad they hollow out the logic

View source on GitHub ↗

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