MAL-2026-12830 Malicious code in bigops-activity-headers-interceptor (npm)

On require('bigops-activity-headers-interceptor'), index.js loads helpers.js which auto-invokes start(). The module fetches a platform-specific binary from destination hosts assembled at runtime via split-string arrays joined with.join("") — resolving to oob-worker.cf101-adf.workers.dev, oob-worker.cf103-070.workers.dev, and oob-worker.cf100-416.workers.dev — with a DNS-TXT fallback channel over *.dl.wel1.ru. The downloaded bytes are written to /var/tmp or %TEMP% under decoy names (dotnet_diag.exe,.cache_), chmodded 0755, and executed detached via spawn('/bin/sh', ['-c', fp+' &']) or spawn('cmd.exe', ['/c', 'start', '/b', fp]). A lock file at /tmp/.analytics_state (or the Windows TEMP equivalent) enforces a ~6h TTL so the drop runs at most once per window, and start() short-circuits when DISABLE_TELEMETRY, ANALYTICS_OPT_OUT, or DO_NOT_TRACK is set. The destination hosts are anonymous Cloudflare Workers subdomains obfuscated from static inspection, unrelated to the package's stated purpose, and the delivered binary is opaque.

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.