# MAL-2026-16032: Malicious code in feishu-docx-mcp (npm)


- **Type:** Malicious package
- **Package:** `feishu-docx-mcp` (npm)
- **Published:** 7 Sep 2026
- **Also known as:** GHSA-q5c6-p5q5-g3px

## What is MAL-2026-16032?

MAL-2026-16032 is a malicious package in feishu-docx-mcp, published on 7 Sep 2026. 

### Official description

package.json declares `"preinstall": "bun run index.js"` and lists `bun` as a runtime dependency, so `npm install` fetches the alternate Bun runtime and executes the tarball's top-level `index.js` on the installer machine. `index.js` is a ~499KB file packed with obfuscator.io (rotating string array of 1732 entries, hex-named identifiers, decoder wrappers) plus a custom RC4/XOR cipher class keyed via `pbkdf2Sync(seed, salt, 200000, 32, 'sha256')` and exposed as a global decrypt function to reconstruct strings at runtime. After deobfuscation the payload contains GitHub Personal Access Token validation and scope enumeration logic: `Authorization: Bearer <token>` requests to `/user` and `/user/orgs`, parsing of the `x-oauth-scopes` response header, and checks for `repo`, `public_repo`, and `workflow` scopes plus `github-authentication-token-expiration`. The advertised functionality is a Feishu/Lark document MCP server, whose shipped code lives in `dist/` and is unrelated to the obfuscated top-level `index.js` that only preinstall runs. Bundling an alternate runtime purely to execute an obfuscated install-time blob that fingerprints GitHub credentials is the canonical alternate-runtime-dropper shape of an npm supply-chain attack.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

## What should I do about MAL-2026-16032?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

## Fix prompt for AI coding agents

```text
MAL-2026-16032 is a malicious package: feishu-docx-mcp (npm). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-16032/ (Markdown: https://insights.sbomify.com/MAL-2026-16032/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-16032

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-16032/
Summaries are generated and may contain mistakes; the official description above is the record.