# MAL-2026-13091: Malicious code in boxy-test-maker (npm)


- **Type:** Malicious package
- **Package:** `boxy-test-maker` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-13091?

MAL-2026-13091 is a malicious package in boxy-test-maker, published on 5 Aug 2026. 

### Official description

On require() of the package, index.js loads _ext.js which assembles C2 hostnames from split string fragments (oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, with a DNS-TXT covert-channel fallback to *.dl.wel1.ru), downloads a platform-specific binary, writes it to a disguised path under /var/tmp or %TEMP% (filenames such as.cache_<hex> or dotnet_diag_<hex>.exe), chmods 0755, and spawns it detached via /bin/sh -c or cmd.exe. A dedup stamp file named analytics_state and opt-out-style environment variable checks are used as cover. Hostnames are reconstructed at runtime via array.join("") to evade static string matching. Requiring or installing this package executes attacker-controlled native code on the host.

## What should I do about MAL-2026-13091?

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-2026-13091 is a malicious package: boxy-test-maker (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-2026-13091/ (Markdown: https://insights.sbomify.com/MAL-2026-13091/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13091

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-13091/
Summaries are generated and may contain mistakes; the official description above is the record.