MAL-2026-11506 Malicious code in beaver-ui-date-range-picker (npm)

[email protected] declares a postinstall hook (node setup.js) and additionally triggers the same script from index.js via try { require('./setup'); } catch (_) {}, so the dropper fires both at npm install and when a consumer requires the package (bypassing --ignore-scripts). setup.js reconstructs a set of Cloudflare Worker hostnames at runtime by joining fragmented string arrays (e.g. oob-worker.cf99-9b3.workers.dev through oob-worker.cf103-070.workers.dev), selects a platform-specific payload path, downloads a binary via https.get, writes it to /tmp or %TEMP% under decoy names such as .cache_<hex> or dotnet_diag_<hex>.exe, chmods 0755 on POSIX, and launches it detached with .unref(). A DNS-TXT covert channel resolves numbered subdomains under *.dl.well1.site and reassembles a base64-encoded payload as an out-of-band fallback delivery path. On Windows the script invokes execSync('powershell...'). The cover story presents the behavior as analytics_state/telemetry, but the package's advertised purpose (a UI date-range picker) has no legitimate need to fetch and execute a native binary from obfuscated non-publisher hosts. Hostname obfuscation, unpinned mutable URLs, absent hash/signature verification, decoy filenames, detached background execution, and a DNS-TXT fallback channel are the fingerprint of a supply-chain dropper.

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.