PyTorch Lightning Compromised in PyPI Supply Chain Attack to Steal Credentials

PyTorch Lightning, a popular Python framework with over 31,100 GitHub stars, was compromised in a supply chain attack with two malicious versions (2.6.2 and 2.6.3) deployed to conduct credential theft.

• •The malicious package contains a hidden _runtime directory with a downloader and obfuscated JavaScript payload that executes automatically upon module import, requiring no user action
• •Attack chain downloads and executes the Bun JavaScript runtime, then runs an 11MB obfuscated malicious payload to harvest credentials from developer and CI/CD environments
• •Stolen GitHub tokens are validated and used to inject worm-like payloads into up to 50 repository branches, with commits impersonating Anthropic's Claude Code using a hardcoded identity
• •Secondary npm propagation vector modifies local npm packages via postinstall hooks, increases patch version, and repacks tarballs for distribution