"The PyPI package ‘lightning’, a widely-used deep learning framework, was compromised in a supply chain attack affecting versions 2.6.2 and 2.6.3 published on April 30, 2026. Teams building image classifiers, fine-tuning LLMs, running diffusion models, or developing time-series forecasters frequently have lightning somewhere in their dependency tree.
Running pip install lightning is all that is needed to activate. The malicious versions contain a hidden _runtime directory with obfuscated JavaScript payload that executes automatically upon module import. The attack steals credentials, authentication tokens, environment variables, and cloud secrets, while also attempting to poison GitHub repositories. It has Shai-Hulud themes including creating public repositories called EveryBoiWeBuildIsaWormBoi."