async-mutex-locknpm
async-mutex-lock is a confirmed malicious npm package (MAL-2026-12513) that steals credentials and exfiltrates sensitive data (malicious version 5.3.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in async-mutex-lock (npm)
What this malware does
The package is advertised as a mutex-lock utility but ships none of the documented API (no Mutex/lock/unlock). Its sole export, getPlugin in index.js, assembles a URL from split protocol/domain/path variables resolving to https://31.97.137.157:45000/icons/108, fetches a JSON response, and passes the response field data.credits to new Function(...) invoked with full require/process/Buffer context — executing attacker-controlled JavaScript on the caller's host. Variable framing references CDN names (cloudflare, fastly, akamai, cdnjs/font-awesome) as a decoy over a bare-IP destination unrelated to any CDN. Declared dependencies (@primno/dpapi, node-machine-id, better-sqlite3, socket.io-client) are consistent with infostealer staging (DPAPI decryption, machine fingerprinting, SQLite reads of browser stores, socket-based C2). The name resembles the popular async-mutex package.
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 async-mutex-lock (version 5.3.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging async-mutex-lock across your stack and pipelines.
If you installed it — respond
async-mutex-lock 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 async-mutex-lock 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 async-mutex-lock 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 async-mutex-lock-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.