hash-investigation

hash-investigation is a skill for Claude Code, Codex from Liberty91LTD/cti-skills. It costs 87 tokens per session (1,884 once invoked), scanned A, original, MIT.

A file-hash investigation workflow for checking identifiers such as MD5, SHA-1, and SHA-256 against malware intelligence sources. It can combine detection results, malware family information, behavior tags, and related infrastructure clues.

In plain words
What is it for?
Use it to investigate a file hash, identify possible malware, find communicating IP addresses or dropped files, and optionally request deeper behavioral analysis.
Why use it?
It gathers security context about a suspicious file without needing separate manual lookups across multiple services. It can also indicate whether a deeper malware analysis is warranted.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to investigate a file hash, identify possible malware, find communicating IP addresses or dropped files, and optionally request deeper behavioral analysis.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/liberty91ltd/cti-skills/hash-investigation
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add Liberty91LTD/cti-skills --skill hash-investigation
Clone the repo
git clone --depth 1 https://github.com/Liberty91LTD/cti-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for hash-investigation

README.md
[![agentmods](https://agentmods.dev/badge/skills/liberty91ltd/cti-skills/hash-investigation/github.svg)](https://agentmods.dev/skills/liberty91ltd/cti-skills/hash-investigation)
Your own site
<a href="https://agentmods.dev/skills/liberty91ltd/cti-skills/hash-investigation"><img src="https://agentmods.dev/badge/skills/liberty91ltd/cti-skills/hash-investigation/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for hash-investigation

Your own site · 80×15
<a href="https://agentmods.dev/skills/liberty91ltd/cti-skills/hash-investigation"><img src="https://agentmods.dev/badge/skills/liberty91ltd/cti-skills/hash-investigation.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 87 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,884 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00087 $0.01884
Opus 5 $0.00044 $0.00942
Sonnet 5 $0.00017 $0.00377
Haiku 4.5 $0.00009 $0.00188

Measured 12d ago against content hash e06090d82678, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

hash-investigation scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/hash-investigation/SKILL.md · 165 lines

How it starts

The opening of the file, as written. The whole thing — 165 lines — stays where its author put it; the contents beside it link to each section on GitHub.

hash-investigation

Investigate a file hash end-to-end. Chain lookups, surface malware family attribution, prioritize infrastructure pivots, and decide whether deeper malware analysis is warranted.

This skill invokes: /lookup-liberty91 (first-party — run first), /lookup-virustotal, /lookup-otx, optionally /lookup-reversinglabs (vendor-authoritative classification + MITRE ATT&CK + sandbox), optionally /lookup-crowdstrike (Falcon Intel verdict + actor/malware attribution), optionally /lookup-misp and/or /lookup-opencti (internal correlation), optionally /lookup-sentinel (exposure check in your own telemetry), optionally /malware-analysis, then /source-assessment, /tlp-guide, /confidence-levels.

When to invoke

  • User asks to check a hash, identify malware, or enrich a sample
  • Another skill surfaces a hash during investigation (e.g., /ip-investigation found communicating files)
  • User asks "what is this malware" with a hash as input

Inputs

indicator: <MD5 | SHA-1 | SHA-256 hash>
context: <optional — where did this hash come from?>
tlp_ceiling: <optional, default AMBER>
request_malware_analysis: <optional bool — trigger /malware-analysis after lookup>

Procedure

1. Validate

  • Confirm the hash is a valid length (MD5=32, SHA-1=40, SHA-256=64 hex chars)
  • Reject if not; route to correct skill if it looks like a different indicator type

2. Parallel lookups

Always run (free / commonly available):

/lookup-virustotal hash <value>    # detection stats, family, behavior tags
/lookup-otx hash <value>           # community pulses, campaign attribution

Add to the same parallel batch if credentials are configured — don't demote these to "later, maybe":

/lookup-reversinglabs hash <value> --av-scanners --ticloud   # if $REVERSINGLABS_USER is set. Vendor-authoritative verdict + threat name + AV detection ratio. RL is the strongest single-source verdict on a hash; run it whenever available, not just when VT signal is thin.
/lookup-crowdstrike indicator <value>                        # if $CROWDSTRIKE_CLIENT_ID is set. Falcon Intel verdict — malicious confidence + the threat actors and malware families CrowdStrike links to this hash + report refs. One API call.
/lookup-liberty91 ioc-lookup <value>                         # if $LIBERTY91_API_KEY is set. First-party — run first: does your own platform already hold this hash, with what verdict, confidence and TLP?
/lookup-misp search-attributes --value <value>               # if $MISP_URL + $MISP_KEY are set. Internal correlation against your own catalogued events.
/lookup-opencti lookup <value>                               # if $OPENCTI_URL + $OPENCTI_TOKEN are set. Internal correlation against your OpenCTI knowledge base (observables + indicators in one call).

Read the full file on GitHub · 165 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 12d ago First seen · 165 lines · 87 tokens per session scan A e06090d82678

Subscribe to this mod's changes

hash-investigation is a skill published in the GitHub repository Liberty91LTD/cti-skills (18 stars, last pushed 1mo ago), licensed MIT. It adds 87 tokens to every session and 1,884 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.