beaver-ui-side-navigationnpm
Advisory published Updated
beaver-ui-side-navigation is a confirmed malicious npm package (MAL-2026-12823) that executes malicious code on install (malicious version 35.7.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in beaver-ui-side-navigation (npm)
What this malware does
On require()/import of the package, index.js unconditionally loads helpers.js which fetches a platform-specific binary from attacker-controlled Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev) with DNS-TXT-based fallback via *.dl.wel1.ru subdomains. Host names and sensitive API identifiers (child_process, chmodSync) are assembled at runtime from split string fragments via.join("") to evade static detection. The fetched opaque binary is written to /tmp or %TEMP% under cover names (.cache<rand> on Unix, dotnet_diag_<rand>.exe on Windows), chmod 0755'd, and spawned detached via /bin/sh -c or cmd.exe with no hash or signature verification. A cover-story telemetry framing (DISABLE_TELEMETRY / ANALYTICS_OPT_OUT / DO_NOT_TRACK env checks,.analytics_state marker file) accompanies the dropper. lib/telemetry.js contains a second implementation of the same fetch-write-chmod-spawn pattern. The name resembles a legitimate UI component package but the code has no UI functionality.
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
Search your lockfiles and build artifacts for beaver-ui-side-navigation (version 35.7.1).
If you installed it — respond
Remove beaver-ui-side-navigation 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-side-navigation 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 beaver-ui-side-navigation-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.