MAL-2026-12480 Malicious code in tms-x-headers (npm)

On require() of the package, helpers.js fetches a platform-specific binary from hostnames assembled by concatenating string fragments (oob-worker.cf101-adf.workers.dev and sibling cf103-070 / cf100-416 workers.dev hosts), with a DNS-TXT fallback channel resolved through fragment-joined *.dl.well1.site names. The fetched bytes are written to a temp file with a cover-story name (dotnet_diag<hex>.exe on Windows,.cache_<hex> on Unix), chmod 0755, and spawned detached via cmd.exe /c start or /bin/sh -c with no hash or signature verification. The child_process module is also required via a split string ("child_" + "process") in lib/telemetry.js. The destination hosts are not the package publisher, are deliberately fragmented to evade static string matching, and the temp filename mimics legitimate.NET diagnostics tooling. Installing or loading the package therefore runs attacker-controlled native code on the installer's host.

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.