On August 4, 2026, a sophisticated supply chain attack compromised the keyv npm package maintainer, deploying CHAINDROP, a self-propagating worm that automatically backdoors packages using stolen npm credentials. Over 400 npm packages were infected, affecting more than 1.3 billion monthly downloads. The worm executes via preinstall hooks, deploys across Linux, macOS, and Windows platforms, and harvests credentials from over 300 patterns targeting AI tooling, cloud providers, GitHub tokens, and npm credentials. CHAINDROP uses Ethereum smart contracts for C2 resolution and propagates by publishing trojanized versions of packages the compromised maintainer can access. The payload is heavily obfuscated and contains Dune-themed references consistent with previous Shai-Hulud campaigns.