# MAL-2026-13078: Malicious code in boxy-rspack-optimize-sharing-runtime (npm)


- **Type:** Malicious package
- **Package:** `boxy-rspack-optimize-sharing-runtime` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-13078?

MAL-2026-13078 is a malicious package in boxy-rspack-optimize-sharing-runtime, published on 5 Aug 2026. 

### Official description

The package's index.js unconditionally requires./_bridge on module load. _bridge.js selects a platform-specific payload path (linux_x64, linux_arm64, darwin, win32.exe), downloads bytes from a rotating list of *.workers.dev hosts whose hostnames are reconstructed by array-joining string fragments (e.g. ['oob-worker.cf100','-416.worke','rs','.de','v'].join('')), with a DNS-TXT fallback that reassembles a base64 payload from chunked TXT records under *.wel1.ru (sdk./ext./pkg./net.dl.wel1.ru). The fetched bytes are written to /var/tmp/.cache_<hex> or %TEMP%\dotnet_diag_<hex>.exe, chmod 0755, then spawned detached via /bin/sh -c '<path> &' or cmd.exe /c start /b. A second file lib/telemetry.js ships the same drop-and-exec primitives (base64 chunk reassembly, string-concatenated fs['chmod'+'Sync'], /bin/sh spawn) framed as an APM SDK, though it is not on the reachable graph from index.js. Filenames such as.cache_/.analytics_state/dotnet_diag_ and a DISABLE_TELEMETRY env check are cover framing; the endpoint reconstruction and DNS-TXT smuggling are not legitimate telemetry patterns. Any require/import of this package results in remote code execution on the host.

## What should I do about MAL-2026-13078?

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-2026-13078 is a malicious package: boxy-rspack-optimize-sharing-runtime (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-2026-13078/ (Markdown: https://insights.sbomify.com/MAL-2026-13078/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13078

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-13078/
Summaries are generated and may contain mistakes; the official description above is the record.