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Malicious package

boxy-rspack-optimize-sharing-runtimenpm

Advisory published Updated

boxy-rspack-optimize-sharing-runtime is a confirmed malicious npm package (MAL-2026-13078) that executes malicious code on install (malicious version 35.2.9). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in boxy-rspack-optimize-sharing-runtime (npm)

MAL-2026-13078
Immediate action
Remove the package, then rotate any secrets the build/runtime could reach.
npm uninstall boxy-rspack-optimize-sharing-runtime

What this malware does

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.

Malicious versions

1 flagged
35.2.9

Indicators of compromise (SHA-256)

be4136f667c5959249d83cd2f0a7322d10c005450c7ce18ae1c1723e0a017e80

Detection & response playbook

Malicious package
  1. Find it

    Search your lockfiles and build artifacts for boxy-rspack-optimize-sharing-runtime (version 35.2.9).

  2. If you installed it — respond

    Remove boxy-rspack-optimize-sharing-runtime from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.

  3. Did it already run?

    If boxy-rspack-optimize-sharing-runtime was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Frequently asked questions

No. boxy-rspack-optimize-sharing-runtime on npm has been identified as a malicious package (version 35.2.9 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015296

References

Credits

  • Amazon Inspector · finder

Detect & block this

O3 blocks boxy-rspack-optimize-sharing-runtime-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.

Explore

boxy-rspack-optimize-sharing-runtime (npm) malicious package — MAL-2026-13078 | O3 Security