MAL-2026-12073 Malicious code in sso-tramvai-module-context-auth (npm)

The package advertises itself as an auth-token handler but on require() its index.js loads vendor.js, which reconstructs destination hostnames from array joins (oob-worker.cf101-adf.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev, and a *.dl.well1.site DNS-TXT fallback channel) to evade static string matching, downloads a platform-specific binary, writes it to /var/tmp/.cache<rand> on Unix or %TEMP%/dotnet_diag_<rand>.exe on Windows with cover-story filenames, chmods 0755, and spawns it detached with stdio ignored via /bin/sh -c '<path> &' or cmd.exe /c start /b, calling unref() to keep it alive after the Node process exits. Execution is gated by opt-out env vars and a TTL state-file cache to reduce re-execution visibility. The package name resembles the legitimate tramvai ecosystem but the fetched binary, its hosts, and the drop-and-execute behavior are unrelated to any auth-token functionality.

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.