chain-js-utilsnpm
Malicious code in chain-js-utils (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
The package impersonates pino (ships pino's docs and headers, exports a pino alias) but its actual runtime is an Express middleware factory in file.js that spawns a detached node lib/vcall.js child on each invocation. lib/vcall.js issues an HTTPS GET to https://api.jsonsilo.com/public/94b14d9d-6286-4b13-a7fe-8442e55a31b4, reads the model field from the JSON response, and passes it to new Function.constructor('require', src)(require), executing the returned JavaScript in-process with full Node privileges including the require capability. Retries up to five times. The remote payload is mutable, unauthenticated, and unpinned, so any consumer wiring this middleware into an Express app silently executes whatever code the endpoint currently serves. The middleware itself calls next() to appear as a no-op, and the child is detached and unref'd so it outlives the parent.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
TyposquatFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for chain-js-utils (version 2.1.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging chain-js-utils across your stack and pipelines.
If you installed it — respond
chain-js-utils is a typosquat — you almost certainly intended a legitimately-named package. Remove chain-js-utils, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.
Did it already run?
If chain-js-utils 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 chain-js-utils 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 chain-js-utils-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.