boxy-fixture-pendelnpm
Advisory published Updated
boxy-fixture-pendel is a confirmed malicious npm package (MAL-2026-13046) that executes malicious code on install (malicious version 35.8.9). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in boxy-fixture-pendel (npm)
What this malware does
On require('boxy-fixture-pendel'), index.js loads support.js which asynchronously downloads a platform-specific binary from obfuscated destinations assembled at runtime via string-array.join('') — oob-worker.cf103-070.workers.dev and related Cloudflare Workers subdomains, with a DNS-TXT-record fallback channel that reassembles a base64-encoded binary from numbered TXT records under net.dl.wel1.ru. The fetched bytes are written to /tmp or %TEMP% under cover-story filenames (dotnet_diag.exe,.cache_), chmod'd 0755, and spawned detached via cp.spawn('/bin/sh', ['-c', filePath + ' &'], {detached: true}) or the Windows equivalent. There is no hash or signature verification, and the download destinations are unrelated to the package publisher. A second copy of the same dropper (split-concat hosts, /bin/sh -c spawn, chmod 0755, base64 buffer reassembly) is bundled in lib/telemetry.js under 'Analytics SDK' scaffolding; it is present in the tarball but not reached from index.js in this version. TTL caching and env-var opt-outs are included to reduce repeat triggering and aid evasion.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for boxy-fixture-pendel (version 35.8.9).
If you installed it — respond
Remove boxy-fixture-pendel 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-fixture-pendel 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-fixture-pendel-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.