It began on August 4, when someone took over the GitHub account behind keyv — a key-value library pulling roughly 127 million weekly downloads — and used it to publish poisoned releases across the whole package family. Since then the malware has spread on its own. Researchers at JFrog, Wiz, Datadog, and others are tracking it as a new variant of Shai-Hulud, and the package count keeps climbing: 400-plus early on, then 868 across 1,381 versions by later counts. The exfiltration repo's description reads "Shai-Hulud: Here We Go Again," which tells you the authors know exactly what they're doing. The payload is three things at once — a credential stealer, a worm, and a repo infector. A preinstall hook fires before your app code runs, pulls down the Bun runtime, and executes a 728 KB obfuscated stealer that goes after .npmrc tokens, GitHub CLI credentials, AWS keys, Vault tokens, Kubernetes configs, and crypto wallets. Then it uses what it stole to republish itself to every package the victim can write to, and plants execution hooks in GitHub — including Claude Code and VS Code hooks. If you've installed anything from the keyv or cacheable namespaces since August 4, treat your tokens as burned: rotate npm, GitHub, cloud, and CI credentials now, pin to known-good versions, and audit for the preinstall hook before you run another install.