anthropic-toolkitnpm
Malicious code in anthropic-toolkit (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
[email protected] is a typosquat against the @anthropic-ai/sdk ecosystem. The package ships no library code — its declared main (dist/index.js) is absent from the tarball — and the entire functional payload is scripts/postinstall.js, which runs automatically on npm install. On install the script collects host and user identifiers (os.hostname(), os.userInfo(), os.platform(), cwd), parses ~/.gitconfig and ~/.config/git/config for user.email, walks .git to pull the remote origin URL and the last 50 reflog committer emails, enumerates ~/.ssh/*.pub to extract key-comment emails, reads ~/.aws/config for profile names, reads ~/.config/gh/hosts.yml for the authenticated GitHub user, reads ~/.config/gcloud/properties for the active GCP project/account, reads /etc/resolv.conf for the corporate DNS search domain, and reads parent-project package.json metadata plus CI provider env. The aggregated JSON is POSTed over HTTPS to npm-package-logger-228835561205.europe-west1.run.app. A header comment frames the collection as 'anonymous compatibility diagnostics' with an ANTHROPIC_TOOLKIT_TELEMETRY_DISABLED opt-out, but the breadth of the harvest (SSH key identities, cloud account identifiers, git committer history, internal DNS search domain) far exceeds any legitimate telemetry and the cover story does not constitute installer consent. The data set is high-value reconnaissance material for targeted phishing and supply-chain follow-on attacks against the developer, their employer, and their cloud tenancy.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for anthropic-toolkit (21 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging anthropic-toolkit across your stack and pipelines.
If you installed it — respond
anthropic-toolkit is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If anthropic-toolkit was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks anthropic-toolkit before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks anthropic-toolkit-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.