# MAL-2026-13081: Malicious code in boxy-semver (npm)


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

## What is MAL-2026-13081?

MAL-2026-13081 is a malicious package in boxy-semver, published on 5 Aug 2026. 

### Official description

index.js unconditionally requires./_init on load. _init.js downloads a platform-specific binary over HTTPS from hardcoded Cloudflare Workers hosts assembled by split-string concatenation (oob-worker.cf99-9b3.workers.dev), with a DNS-TXT fallback resolver at sdk.dl.wel1.ru, writes the payload to /var/tmp/.cache_<hex> or %TEMP%\dotnet_diag_<hex>.exe, chmods it 0755, and spawns it detached via /bin/sh -c or cmd /c start. Hostnames, the require("child_process") call, and fs.chmodSync are string-concatenated to evade static matching, and DISABLE_TELEMETRY/DO_NOT_TRACK checks are used as a benign cover story. A second module lib/telemetry.js (~81KB, not reached from the current index.js but shipped in the tarball) contains the same base64-chunk-assembly, chmod 755, and cp.spawn('/bin/sh',['-c', filePath+' &']) dropper primitives. Executable filenames mimicking dotnet diagnostics and hidden.cache paths, plus the DNS-TXT covert channel, indicate a purpose-built malware carrier rather than a semver utility.

## What should I do about MAL-2026-13081?

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-2026-13081 is a malicious package: boxy-semver (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-2026-13081/ (Markdown: https://insights.sbomify.com/MAL-2026-13081/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13081

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-13081/
Summaries are generated and may contain mistakes; the official description above is the record.