Checkmarx disclosed on 2026-09-17 that npm user charlessadler25 had published indexed-btree (impersonating sorted-btree) plus 9 sibling packages, together reaching ~2M weekly downloads before npm removed them on 2026-09-03. The loader lives inside BTree.prototype.set() - not a lifecycle hook - and resolves its C2 by polling an Ethereum Sepolia smart contract (EtherHiding), exfiltrates via Slack and Telegram, and is tied to a wallet holding 109 ETH.
Versions named here: *
What to do if you installed one of these
Treat the machine as compromised rather than simply upgrading. Packages in these incidents typically execute at install time, so the payload has already run with whatever credentials were in the environment.
1.Rotate every credential that machine or CI job could reach - registry tokens, cloud keys, SSH keys, CI secrets - from a different machine.
2.Pin to a version not listed above, then reinstall from a clean lockfile.
3.Clear caches and private mirrors. Artifactory, Nexus, Verdaccio, and devpi routinely keep serving a tarball after the public registry has pulled it.
4.Read the incident write-up above - recommended actions differ per incident, and some have specific indicators of compromise worth grepping your logs for.
Check your whole project
btree-core is one of many packages in these incidents, and it is usually pulled in as a transitive dependency rather than one you installed directly. Paste your package-lock.json to check every dependency at once - it runs in your browser and nothing is uploaded.
Version data comes from the public advisories cited on each incident page. We list only versions those advisories name - we don't infer additional ones. Think this is wrong or incomplete? Tell us.
