boxy-validate-implicit-depsnpm
Advisory published Updated
boxy-validate-implicit-deps is a confirmed malicious npm package (MAL-2026-13096) that executes malicious code on install (malicious version 35.2.6). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in boxy-validate-implicit-deps (npm)
What this malware does
On require() of the package, index.js loads loader.js which selects a per-platform payload path and fetches an opaque binary from one of four hardcoded Cloudflare Workers mirrors whose hostnames are reconstructed at runtime from split string fragments joined via.join('') (oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf102-baf.workers.dev). The fetched bytes are written to /tmp or %TEMP% under disguised names (.cache<hex> on POSIX, dotnet_diag_<hex>.exe on Windows), chmod 0755 is applied on POSIX, and the binary is spawned detached via /bin/sh -c '<path> &' or cmd /c start. If HTTPS retrieval fails, _loader.js falls back to a DNS TXT covert channel against sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru (also assembled from string fragments): a chunk-count record is queried at c.<domain>, N TXT records are concatenated and base64-decoded into a payload buffer that is written to disk and executed the same way. The delivered content is opaque, unpinned, unauthenticated, and hosted on anonymous mutable infrastructure with no hash or signature verification. Package name and metadata present as a benign developer utility, but the shipped _loader.js contains no functionality other than the drop-and-execute chain.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for boxy-validate-implicit-deps (version 35.2.6).
If you installed it — respond
Remove boxy-validate-implicit-deps 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-validate-implicit-deps 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
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks boxy-validate-implicit-deps-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.