boxy-rspack-optimize-sharing-runtimenpm
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)
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
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for boxy-rspack-optimize-sharing-runtime (version 35.2.9). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging boxy-rspack-optimize-sharing-runtime across your stack and pipelines.
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.
Did it already run?
If boxy-rspack-optimize-sharing-runtime was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks boxy-rspack-optimize-sharing-runtime before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
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.