MAL-2026-12823 Malicious code in beaver-ui-side-navigation (npm)

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.