beaver-ui-hooksnpm
beaver-ui-hooks is a confirmed malicious npm package (MAL-2026-12146) that executes malicious code on install (malicious versions 12.6.3, 34.4.2, 35.3.5). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in beaver-ui-hooks (npm)
What this malware does
The package's declared main (index.js) unconditionally loads ext.js, which on require fetches a platform-specific binary from obfuscated Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev), writes it to a temporary path under hidden filenames (.cache<hex> on Unix, dotnet_diag_<hex>.exe on Windows), sets executable permissions via fs.chmodSync(path, 0o755), and spawns it detached via cp.spawn("/bin/sh", ["-c", fp+" &"], {detached:true}) or cmd. When HTTPS fetch fails, _ext.js falls back to DNS TXT resolution against *.dl.wel1.ru (sdk., ext., pkg., net.), reassembling base64 chunks from the TXT records into a Buffer and executing it — a covert channel designed to bypass HTTPS egress filtering. Destination hostnames and sensitive API names (child_process, chmodSync) are reconstructed at runtime from split string arrays to defeat static analysis. Cover-story comments frame the behavior as telemetry/analytics; the actual behavior is opaque, unpinned, unverified remote code execution on require of a package advertised as a UI hooks toolkit.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
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-hooks (3 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-hooks across your stack and pipelines.
If you installed it — respond
Remove beaver-ui-hooks 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-hooks 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-hooks 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-hooks-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.