Artefact triage and preservation
Treat every unknown file as a crime scene: what you touch, you alter. Stabilise before you study.
When to use
First contact with an unknown artefact: a binary, document, firmware image, disk or memory capture, archive or email attachment.
Procedure
- Work on copies only. The original becomes read-only evidence immediately; every derived copy records the original's SHA-256.
- Identify before tools touch it: file signature/magic, container structure, hashes, size, timestamps. Treat
fileoutput as a hypothesis — packed or malformed files lie. - Establish provenance: where it came from, when, from whom; record the acquisition channel. A sample without provenance is reported as such.
- Choose the containment level before any execution: presumed hostile unless the owner's scope says otherwise. Execution decisions belong to the runtime-investigation stage, never the triage stage.
- Package evidence: archive (original + hashes + notes + tool versions + a timeline of every action taken) with a manifest that lets a stranger reproduce the workspace.
- Triage depth ladder: signature → container/packer hints → strings (as hints, not conclusions) → imports/capabilities (hypotheses) → deeper analysis only with a written question the step will answer.
- Timebox the pass: triage aims to route the artefact (what is it, how dangerous to handle, what it likely is) — not to answer every question.
Decision rules
- An execution decision made during triage is a defect: route, do not run.
ldd, debuggers and instrumentation are not read-only operations; if a tool can execute or modify the artefact, it does not belong in triage.- If identification is ambiguous (packed, obfuscated, unusual entry), say so and hand over the ambiguity, not a forced guess.
- Archive integrity is part of done: the manifest verifies, or the triage is not done.
Pitfalls
- Opening archives with auto-extraction tools that execute contained code or follow links.
- Treating strings/imports as evidence of behaviour rather than capability hints.
- Losing timestamps by copying without preserving metadata.
Done
An evidence package with verified hashes, provenance, identification with stated confidence, containment decision, routing recommendation and retained ambiguity.


