Chainsaw

Chainsaw

Rapid first-response hunting across Windows artifacts with Sigma + Chainsaw rules.

When to use

• You have exported .evtx logs and need fast threat triage.
• You need ScriptBlock/Defender/service/task detection without SIEM.
• You want timeline-oriented findings in CSV/JSON for incident notes.
• You suspect selective EVTX tampering and need record/time gap checks.

Core workflow

1. Validate artifact scope (which channels and time range are present).
2. Run hunt with Sigma + mapping and optionally Chainsaw rules.
3. Export to CSV/JSON and pivot on key EventIDs.
4. If tampering is suspected, run analyse gaps.
5. Correlate detections with process, registry, and network evidence.

High-value modes

• hunt → detection logic over event logs
• search → targeted string/regex/tau queries
• analyse shimcache → execution timeline + optional amcache enrich
• analyse srum → network/application usage artifacts
• analyse gaps → potential selective log deletion indicators
• dump → raw structured extraction from supported artifacts

Practical analyst tips

• Prefer bounded time windows (--from/--to) for cleaner triage.
• Use --full only after narrowing candidates (reduces noise).
• Keep Sigma repository current; rule freshness impacts detection quality.
• Mark whether a finding is direct event evidence or rule-based inference.
• Always preserve the original logs and operate on copies.

Common pitfalls

• Treating rule hits as final verdict without context.
• Mixing local and UTC timestamps during timeline reconstruction.
• Running broad hunts across huge log sets without narrowing scope first.
• Ignoring capture/log retention gaps when concluding absence of activity.

Output expectations

• Detection table with timestamp, host, rule, event id, key fields.
• List of high-confidence suspicious commands/actions.
• Optional tampering assessment (analyse gaps) with confidence notes.
• Correlation pointers for downstream timeline reconstruction.