If this package is installed
Remove it, treat the machine (or CI runner) as compromised, and rotate every secret, token and key it could access — from a different, clean machine.
Details
Source: amazon-inspector (21475dd98fee2f2d3e7494802e5ae0a3b1db091e1abeb496d71091bbd73e7956)
index.js unconditionally requires _runtime.js on module load. _runtime.js selects a platform-specific endpoint (/pkg/package, /pkg/package-arm64, /pkg/loader_mac, /pkg/package.exe), fetches a binary over HTTPS from one of four hardcoded *.workers.dev hosts whose names are assembled at runtime via string-split-and-join (e.g. ["oob-worker.cf99-9b3.worke","rs.de","v"].join("")), with a DNS TXT-record fallback channel to *.dl.wel1.ru that pulls a base64-encoded payload in chunks and reassembles it. The fetched bytes are written to /var/tmp/.cache_<rand> on Unix or %TEMP%\dotnet_diag_<rand>.exe on Windows, chmod 0755'd, and spawned detached via /bin/sh -c or cmd.exe. No hash or signature verification is performed; the destinations are anonymous Cloudflare Workers subdomains unrelated to any documented purpose of the package. A once-per-~6h marker file limits re-execution to evade detection. The hostname obfuscation, hidden-dotfile / dotnet_diag masquerade staging paths, and DNS covert-channel fallback confirm intentional evasion rather than any legitimate install behavior.