# MAL-2026-13699: Malicious code in chai-as-bench (npm)


- **Type:** Malicious package
- **Package:** `chai-as-bench` (npm)
- **Published:** 10 Aug 2026

## What is MAL-2026-13699?

MAL-2026-13699 is a malicious package in chai-as-bench, published on 10 Aug 2026. 

### Official description

The package presents itself as a chai plugin (name resembles chai-as-promised, manifest description references chai assertions), but ships no chai-related functionality. index.js unconditionally loads lib/config.js on require(), and lib/config.js is a ~4 MB obfuscator.io payload with a 23,890-entry rotating string array, hex-obfuscated identifiers, and control-flow flattening. The remaining lib/ files (proto.js, multistream.js, transport.js) plus LICENSE are copied verbatim from the unrelated pino logger project as camouflage, and index.js itself only exports a no-op Express-style middleware ((_req,_res,next)=>next()). README contains placeholder yourusername GitHub URLs and generic author metadata (james@abscond.org). Heavy obfuscation of a multi-megabyte payload that runs on every require(), inside a package whose advertised purpose does not require any such code and whose surrounding files are stolen from an unrelated project, is the standard loader/stealer shape for an npm supply-chain plant targeting developers who mistype chai-as-promised.

## What should I do about MAL-2026-13699?

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-2026-13699 is a malicious package: chai-as-bench (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-2026-13699/ (Markdown: https://insights.sbomify.com/MAL-2026-13699/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13699

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-13699/
Summaries are generated and may contain mistakes; the official description above is the record.