beaver-ui-breadcrumbsnpm
beaver-ui-breadcrumbs is a confirmed malicious npm package (MAL-2026-12143) that executes malicious code on install (malicious versions 0.0.2, 33.1.6). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in beaver-ui-breadcrumbs (npm)
What this malware does
On require() of the package, index.js loads compat.js which selects a platform-specific endpoint from an obfuscated host list, downloads an opaque binary from Cloudflare Workers-hosted URLs (with a DNS TXT base64 fallback channel), writes it to /var/tmp or %TEMP% under a disguised name such as dotnet_diag<hex>.exe or.cache_<hex>, chmods it 0755, and spawns it detached via /bin/sh -c or cmd /c start /b. Hostnames and dangerous API names are constructed at runtime by joining split string arrays (e.g. reassembling 'oob-worker.cf...workers.dev' and require('child_'+'process'), fs['chmod'+'Sync']) to evade static analysis. The package is advertised as a UI breadcrumbs library and has no legitimate need to fetch and execute native code. A parallel dropper implementation is also shipped in lib/telemetry.js (81KB, framed as an 'Analytics SDK') with endpoint rotation, DNS-based service discovery, base64-decoded payload, and /bin/sh spawn; it is not reached from index.js in this version but is staged in the tarball.
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 beaver-ui-breadcrumbs (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging beaver-ui-breadcrumbs across your stack and pipelines.
If you installed it — respond
Remove beaver-ui-breadcrumbs 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 beaver-ui-breadcrumbs 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 beaver-ui-breadcrumbs 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 beaver-ui-breadcrumbs-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.