Which versions of mutex-thread are malicious?

The following npm versions of mutex-thread are flagged malicious: 1.3.0. Treat any of these as compromised.

How do I remediate mutex-thread if I installed it?

mutex-thread 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.

I already installed mutex-thread — how do I know if it already compromised me?

If mutex-thread 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.

Is mutex-thread part of a known attack campaign?

Yes — mutex-thread is associated with the IN-MAL-2026-018228 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find mutex-thread across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for mutex-thread (version 1.3.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging mutex-thread across your stack and pipelines.

Malicious package

mutex-threadnpm

mutex-thread is a confirmed malicious npm package (MAL-2026-14185) that steals credentials and exfiltrates sensitive data (malicious version 1.3.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in mutex-thread (npm)

MAL-2026-14185

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall mutex-thread

What this malware does

The package presents itself as a mutex library but lib/Mutex.js contains an injected branch in runExclusive that, when a caller passes callback.meta.jobId === 'cross-chain-transfer', spawns lib/withLoad.min.js as a detached node child with stdio ignored and windowsHide true. lib/withLoad.min.js is a hex/base64-obfuscated dropper that reads an encrypted key from a Sepolia Ethereum smart contract (via eth-sepolia.g.alchemy.com and sepolia.infura.io RPC endpoints), derives a shared secret, decrypts payloads hosted on the contract, writes them to disk, chmods 755, and re-spawns node on them. Before entering its command loop it collects host reconnaissance (os.platform, release, arch, hostname, cpus, totalmem, freemem, uptime) and posts it to a hardcoded Slack bot via slack.com/api/chat.postMessage and to a hardcoded Telegram bot at api.telegram.org/bot<token>/sendMessage. lib/tryLoad.min.d.js polls slack.com/api/conversations.history every ~10 seconds with a hardcoded bearer token and channel id, reassembles chunked messages, AES-GCM-decrypts them using a key passed via argv, writes the plaintext to withLoad.min.js, chmods 755, and spawns node on it; an 'exitexitexit' sentinel triggers self-deletion of loader files and killing of a peer PID. String-array rotation and base64 wrapping are used to hide C2 hosts, bot tokens, channel ids, and the Sepolia contract address.

Malicious versions

1 flagged

1.3.0

Indicators of compromise (SHA-256)

e142539248a690ef78ebe7ceeaa4c16e9903107a04704e1947cf296bce543097

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for mutex-thread (version 1.3.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging mutex-thread across your stack and pipelines.
If you installed it — respond
mutex-thread 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 mutex-thread 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 mutex-thread 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

No. mutex-thread on npm has been identified as a malicious package (version 1.3.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-018228

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks mutex-thread-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

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