MAL-2026-12151 Malicious code in bigops-auth-interceptor (npm)

On require() of [email protected], index.js loads vendor.js which selects a platform-specific binary URL, downloads bytes over HTTPS from one of four string-concatenation-obfuscated Cloudflare Workers mirrors (oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf100-416.workers.dev), writes them to a temp path under a disguised name (dotnet_diag<hex>.exe on Windows,.cache_<hex> on Linux), chmods 0755, and spawns the file detached via /bin/sh -c or cmd.exe. A DNS TXT-record fallback channel (c.<domain> returns a chunk count, then i.<domain> TXT records are concatenated and base64-decoded into the payload) is implemented against sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru, providing covert payload retrieval when HTTPS is blocked. A run-once marker file (.analytics_state) prevents repeated execution. Destination hosts are unrelated to any legitimate publisher of the package's stated purpose; the fetched bytes are unpinned, unsigned, and platform-selected.

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.