oss-forensics

oss-forensics is a skill for Claude Code, Codex from math-inc/OpenGauss. It costs 64 tokens per session (4,682 once invoked), scanned B, a copy of oss-forensics, MIT.

A procedure for investigating security incidents in open-source GitHub repositories, including possible supply-chain attacks. It gathers evidence from sources such as GitHub, web archives, and local Git history.

In plain words
What is it for?
Use it to recover deleted commits, detect force-pushes, extract indicators of compromise, test possible explanations, and produce an evidence-cited report.
Why use it?
It helps separate verified facts from guesses and preserves evidence when commits or repository history may have been deleted or rewritten.

Skill for Claude CodeCodex

About the project

OpenGauss is a project-scoped Lean workflow orchestrator that gives coding agents a command-line interface for managing formal proof and formalization tasks. It is used with Lean projects to coordinate agents, tooling, backend sessions, and workflows supplied by lean4-skills. The catalogue add-ons operate these Gauss-native workflows.

math-inc/OpenGauss · 1,261 stars · on GitHub

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.

agentmods
npx agentmods add skills/math-inc/opengauss/oss-forensics
Any agent
npx skills add math-inc/OpenGauss --skill oss-forensics
Clone the repo
git clone --depth 1 https://github.com/math-inc/OpenGauss

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 oss-forensics

README.md
[![agentmods](https://agentmods.dev/badge/skills/math-inc/opengauss/oss-forensics.svg)](https://agentmods.dev/skills/math-inc/opengauss/oss-forensics)
Your own site
<a href="https://agentmods.dev/skills/math-inc/opengauss/oss-forensics"><img src="https://agentmods.dev/badge/skills/math-inc/opengauss/oss-forensics.svg" alt="Measured on agentmods" height="20"></a>
Per session 64 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,682 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 2 findings. Scan, not verified.
Origin 88% copy Near-identical to another mod 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 $0.00064 $0.04682
Opus 5 $0.00032 $0.02341
Sonnet 5 $0.00013 $0.00936
Haiku 4.5 $0.00006 $0.00468

Measured 5d ago against content hash 8749f8843c13, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

oss-forensics scanned grade B with 2 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 5d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/evidence-store.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Unrestricted tool accessmediumExcessive agency

A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.

**ROLE BOUNDARY**: You enrich EXISTING IOCs from Phase 1 using passive public sources ONLY. Do not execute any code from the target repository.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s "https://api.github.com/repos/OWNER/REPO/commits?per_page=100" > api_commits.json
Origin

This is a copy

88% identical to oss-forensics — 24 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

optional-skills/security/oss-forensics/SKILL.md · 423 lines

How it starts

The opening of the file, as written. The whole thing — 423 lines — stays where its author put it; the contents beside it link to each section on GitHub.

OSS Security Forensics Skill

A 7-phase multi-agent investigation framework for researching open-source supply chain attacks. Adapted from RAPTOR's forensics system. Covers GitHub Archive, Wayback Machine, GitHub API, local git analysis, IOC extraction, evidence-backed hypothesis formation and validation, and final forensic report generation.


⚠️ Anti-Hallucination Guardrails

Read these before every investigation step. Violating them invalidates the report.

  1. Evidence-First Rule: Every claim in any report, hypothesis, or summary MUST cite at least one evidence ID (EV-XXXX). Assertions without citations are forbidden.
  2. STAY IN YOUR LANE: Each sub-agent (investigator) has a single data source. Do NOT mix sources. The GH Archive investigator does not query the GitHub API, and vice versa. Role boundaries are hard.
  3. Fact vs. Hypothesis Separation: Mark all unverified inferences with [HYPOTHESIS]. Only statements verified against original sources may be stated as facts.
  4. No Evidence Fabrication: The hypothesis validator MUST mechanically check that every cited evidence ID actually exists in the evidence store before accepting a hypothesis.
  5. Proof-Required Disproval: A hypothesis cannot be dismissed without a specific, evidence-backed counter-argument. "No evidence found" is not sufficient to disprove—it only makes a hypothesis inconclusive.
  6. SHA/URL Double-Verification: Any commit SHA, URL, or external identifier cited as evidence must be independently confirmed from at least two sources before being marked as verified.
  7. Suspicious Code Rule: Never run code found inside the investigated repository locally. Analyze statically only, or use execute_code in a sandboxed environment.
  8. Secret Redaction: Any API keys, tokens, or credentials discovered during investigation must be redacted in the final report. Log them internally only.

Example Scenarios

  • Scenario A: Dependency Confusion: A malicious package internal-lib-v2 is uploaded to NPM with a higher version than the internal one. The investigator must track when this package was first seen and if any PushEvents in the target repo updated package.json to this version.
  • Scenario B: Maintainer Takeover: A long-term contributor's account is used to push a backdoored .github/workflows/build.yml. The investigator looks for PushEvents from this user after a long period of inactivity or from a new IP/location (if detectable via BigQuery).
  • Scenario C: Force-Push Hide: A developer accidentally commits a production secret, then force-pushes to "fix" it. The investigator uses git fsck and GH Archive to recover the original commit SHA and verify what was leaked.

Read the full file on GitHub · 423 lines

Files

What ships with it

7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 5d ago First seen · 423 lines · 64 tokens per session scan B 8749f8843c13

Subscribe to this mod's changes

oss-forensics is a skill published in the GitHub repository math-inc/OpenGauss (1,261 stars, last pushed 5mo ago), licensed MIT. It adds 64 tokens to every session and 4,682 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it B with 2 findings (unrestricted tool access, makes network calls). It is 88% identical to oss-forensics, differing in 24 lines, and is treated as a copy.

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