# MAL-2026-10621: Malicious code in chai-as-hardened (npm)


- **Type:** Malicious package
- **Package:** `chai-as-hardened` (npm)
- **Published:** 14 Jul 2026

## What is MAL-2026-10621?

MAL-2026-10621 is a malicious package in chai-as-hardened, published on 14 Jul 2026. 

### Official description

On require, index.js spawns a detached Node child process running lib/initializeCaller.js. That script base64-decodes a hardcoded URL (tomato-brunhilda-40.tiiny.site/index.json) via atob, fetches the response with axios, and executes the response body through the Function constructor with `require` injected, granting the remote payload full Node capabilities on the installer's machine. The destination URL and request header are stored as base64 strings in a shadowed local `process.env` object to hide the target from static review. Package metadata is a cover story: the name resembles chai-as-promised, the description references vulnerability management, and exports mimic pino (module.exports.pino = middleware) with keywords 'logger', 'stream', 'json' to attract developers into installing and requiring it, at which point the remote-execution chain fires.

## What should I do about MAL-2026-10621?

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-2026-10621 is a malicious package: chai-as-hardened (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-2026-10621/ (Markdown: https://insights.sbomify.com/MAL-2026-10621/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-10621

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-10621/
Summaries are generated and may contain mistakes; the official description above is the record.