MAL-2026-12837 Malicious code in bigops-tcrm-auth (npm)

The package's main (index.js) requires./setup on load. setup.js selects a platform-specific payload path, downloads a native binary over HTTPS from Cloudflare Workers subdomains whose hostnames are reassembled at runtime via array-join fragments (e.g. ["oob","-worker.c","f101-adf.workers.d","ev"].join("")), with a DNS-TXT fallback that base64-reassembles the payload from *.dl.wel1.ru resolvers. The downloaded bytes are written to /tmp or %TEMP% under a disguised name (.cache_<hex> on POSIX, dotnet_diag_<hex>.exe on Windows), chmod 0755'd on POSIX, and detached-spawned via /bin/sh -c or cmd /c start. Sensitive APIs are also fragmented (require("child_" + "process"), fs["chmod" + "Sync"]) to evade string matching. A sibling module lib/telemetry.js (3061 lines) presents itself as an "analytics SDK" but reproduces the same dropper primitives at larger scale (HTTPS endpoint rotation, DNS-based service discovery, base64 chunk assembly, chmod 0755, /bin/sh -c spawn). The package advertises itself as an authentication module, a purpose that has no legitimate need to fetch and execute a native binary from obfuscated hosts on import.

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.