Claude-night-market supply-chain-advisory

Overview

Supply chain attacks bypass traditional code review by compromising upstream dependencies. This skill provides patterns for detecting, preventing, and responding to compromised packages in Python ecosystems.

When To Use

• After a supply chain advisory is published
• When auditing dependencies for a new or existing project
• During incident response for a suspected compromise
• When adding the SessionStart hook to a project

When NOT To Use

• General CVE triage unrelated to dependency supply chain
• Application-level vulnerability scanning (use a SAST tool)
• License compliance audits (different concern)

Known-Bad Versions Blocklist

The blocklist lives at

${CLAUDE_SKILL_DIR}/known-bad-versions.json

1. SessionStart hook — warns per-session when compromised versions detected

2. make supply-chain-scan

   — CI/local scanning target
3. This skill — manual audit guidance

Blocklist Format

{
  "package_name": [{
    "versions": ["x.y.z"],
    "date": "YYYY-MM-DD",
    "description": "What the attack did",
    "indicators": ["files or patterns to search for"],
    "source": "advisory URL",
    "severity": "critical|high|medium"
  }]
}

Adding a New Entry

1. Add the entry to

   ${CLAUDE_SKILL_DIR}/known-bad-versions.json

2. Add version exclusions (

   !=x.y.z

   ) to affected

   pyproject.toml

   files
3. Document in

   docs/dependency-audit.md

   under Supply Chain Incidents
4. Run

   make supply-chain-scan

   to verify detection works

Quick Scan Commands

Check all lockfiles on machine for known-bad versions

# Scan uv.lock files for a specific compromised version
grep -r "package_name.*version" --include="uv.lock" /path/to/projects

# Search for malicious artifacts
find /path/to/projects -name "suspicious_file.pth" 2>/dev/null

# Check installed versions in virtualenvs
find /path/to/projects -path "*/.venv/lib/*/PACKAGE*/METADATA" \
  -exec grep "^Version:" {} +

Verify lockfile hash integrity

uv.lock

uv sync

Defense Layers

!=

Limitations

• Zero-day supply chain attacks have no prior advisory — lockfile hashes are the only automatic defense during the attack window
• Safety/CVE databases lag behind real-world compromises
• OSV provides broader coverage but is still reactive