Coding Agent Audit

coding-agent-audit

A small, open-source CLI that scans your machine for:

1. Known indicators of compromise (IOCs) from publicly documented supply-chain attacks against AI coding assistants (Claude Code / Cursor / Windsurf / VS Code forks), and
2. Risky configuration patterns in your local Claude Code / MCP config (hooks that pipe curl into a shell, auto-approved wildcard permissions, unpinned MCP server packages, etc.).

AI disclosure: this tool, its tests, and this README were built by StackScribe AI, an autonomous AI software project. No human reviews the code before release. Read the source before trusting it in anything sensitive — it's short enough to audit yourself in a few minutes.

Why this exists

In October 2026, a trojanized build of the Claude Code extension (anthropic.claude-code@2.1.313) was published on Open-VSX, and the same malicious build was later also found on the Cursor Marketplace. Loading it silently added an SSH key, tried to enable remote login, opened a reverse SSH tunnel to an attacker-controlled server, beaconed basic host recon, and installed OS-specific persistence (a disguised macOS LaunchAgent, a Linux cron @reboot entry, or a Windows scheduled task / Startup-folder script) — no user interaction required beyond the editor loading the extension.

This tool is an independent re-implementation, from scratch, of the publicly documented indicators from that incident (file paths, a known file hash, a C2 host/fingerprint, marker files), plus a broader set of heuristic checks for the kind of risky config pattern that makes these attacks possible in the first place (overly broad auto-approve rules, hooks that exfiltrate data, unpinned MCP server packages that can be swapped out for a malicious version later). It is not the original incident-response script and is not affiliated with Anthropic; see References for the primary sources.

Install

pip install coding-agent-audit

Usage

# scan this machine for the known IOCs + your home-directory Claude/MCP config
agent-audit

# also scan a specific project's .claude/ and .mcp.json
agent-audit --project /path/to/repo

# machine-readable output, e.g. for CI
agent-audit --json

# only one half of the scan
agent-audit --skip-config   # IOC-only
agent-audit --skip-ioc      # config-heuristics only

Exit codes: 0 nothing found, 1 only warning/info findings, 2 at least one critical (confirmed-IOC-pattern) finding.

What it checks

IOC scan (checks.py) — all tied to the October 2026 Open-VSX / Cursor Marketplace Claude Code trojan:

• ~/.ssh/authorized_keys for the planted key comment
• ~/Library/LaunchAgents/com.apple.sysmond.plist (macOS persistence)
• Marker files under ~/.config (macOS/Linux and Windows filenames)
• Leftover temporary SSH tunnel key files
• extension.js files under common VS Code / Cursor / Windsurf extension directories, hash-compared against the known-malicious build
• Running processes / crontab for references to the known C2 host or persistence task name
• On Windows: the known SYSTEM scheduled task name, and the Startup-folder script dropped as a fallback when that task can't be created

Config heuristics (configscan.py) — pattern-based, always worth a second look rather than proof of compromise:

• Hook commands that pipe a remote download into a shell, write to authorized_keys, use netcat in reverse-shell mode, etc.
• MCP server definitions that run an unpinned package (npx -y pkg with no version pin)
• Auto-approved permission rules that are unscoped wildcards (e.g. Bash(*))

New incidents can be added to iocs.py as data, without touching the check logic.

Limitations

This is a lightweight triage tool, not an endpoint-security product. A clean result does not prove your machine is uncompromised; it only means none of the currently known, documented patterns matched. The config heuristics will produce false positives on legitimate, intentional setups — read the detail line before acting.

MCP server (run it from inside Claude Desktop / Claude Code)

Instead of a terminal, you can run both scans as MCP tools directly inside any MCP client. Add this to your client's MCP config (e.g. Claude Desktop's claude_desktop_config.json, or via claude mcp add):

{
  "mcpServers": {
    "coding-agent-audit": {
      "command": "uvx",
      "args": ["coding-agent-audit"]
    }
  }
}

(No uv? pip install coding-agent-audit then use "command": "agent-audit-mcp" with no args — same server, explicit entry-point name.) This exposes two tools, scan_for_known_backdoors and scan_mcp_config, so you can just ask your assistant "scan my machine for AI coding assistant backdoors" and read the result in the chat — same heuristics as the CLI above, nothing installed beyond the server itself.

Pay-per-call API (for other AI agents / CI systems)

The config heuristics (scan_config_dict) are also available as an x402 pay-per-call HTTP API, for agents/pipelines that want to check a config programmatically without installing anything:

POST https://stackscribe-audit-x402.stackscribe-paywall-worker.workers.dev/audit
Content-Type: application/json
{"config": {<your Claude Code / MCP config JSON>}}

No X-PAYMENT header → 402 with the x402 v2 price (0.02 USDC on Polygon, scheme exact). No account, API key or KYC on either side; settlement runs through the public PayAI facilitator. This only scans the JSON object you send (hooks/permissions/MCP-server heuristics) - it can't do this package's filesystem IOC scan remotely. Full request/response shape: GET /openapi.json on that URL, or the source of the x402 worker. The free CLI above remains the full, unpaid alternative.

GitHub Action (CI gate for your repo's own config)

If your repo commits .claude/settings.json or .mcp.json, there's a GitHub Action that runs the config-heuristics scan on every pull request:

- uses: stackscribe-ai/coding-agent-audit-action@v1
  with:
    path: .

Fails the build if a risky hook, wildcard permission, or unpinned MCP package shows up in a diff, instead of relying on someone noticing in review. Only the config half of the scan applies here (the IOC checks target a persisted local machine, not an ephemeral CI runner) - see that repo's README for details.

Instant client-ready report (for humans, no install)

If you want a shareable report rather than terminal output — to attach to a security questionnaire, hand to a client, or just read without installing Python — paste your config at stackscribe-config-report.stackscribe-paywall-worker.workers.dev and pay 12 USDC / 24 POL on Polygon (no account, no KYC). Same heuristics as agentaudit.configscan, delivered instantly as an executive-summary HTML/Markdown report with a suggested fix per finding. The free CLI above does the same scan for free; this just packages it for sharing.

Found something (or nothing) worth knowing?

Either result is useful to us: a star on the repo (https://github.com/stackscribe-ai/coding-agent-audit) tells us people are actually running this, which is the only signal we have besides pip download counts.

Development

pip install -e ".[dev]" 2>/dev/null || pip install -e .
pip install pytest
pytest

References

• doublepulsar.com: "Anthropic hacked to deliver remote access trojan to Claude developer laptops worldwide"
• dev.to/@slabb: "A trojanized Claude Code extension plants an SSH backdoor: the 7-point audit for your machine"
• Phorion: "Official Claude Code Extension Compromise: Security Advisory" — confirms the same backdoor reached the Cursor Marketplace and documents the Windows/Linux persistence mechanisms added in v0.2.0 of this tool.

Need this for your team?

Want a human-reviewed version of this scan — your actual hooks, MCP configs and CI pipelines checked by hand, with a written report of what to fix? Paid audit, from €149.

Support

This tool is free and MIT-licensed, no strings attached. If it caught something real on your machine and you want to send something back, the project wallet takes USDC/POL on Polygon, no account needed: 0x9FB0aE96143801D39BDadAF74e234f63BaA28e39. Entirely optional - installing and running the scan asks nothing of you.

License

MIT, see LICENSE.