chain-chai-testnpm
chain-chai-test is a confirmed malicious npm package (MAL-2026-5908) that opens a backdoor for remote access (malicious version 1.3.5). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in chain-chai-test (npm)
What this malware does
[email protected] advertises itself as a pino-style logger (keywords fast/logger/stream/json, exported alias module.exports.pino = middleware, pino-pretty visual assets) but the exported middleware factory spawns a detached node lib/caller.js process. caller.js performs axios.get against https://jsonkeeper.com/b/EXSIF (with a base64-obfuscated sibling URL https://jsonkeeper.com/b/ZK45J in lib/const.js, decoded from aHR0cHM6Ly9qc29ua2VlcGVyLmNvbS9iL1pLNDVK), reads .data.cookie from the response, and passes that string to new Function.constructor("require", s) invoked with the host process's require. That executes attacker-controlled JavaScript with full Node.js privileges in the consuming application. The fetch destination is an anonymous, mutable JSON-paste host, the URL is duplicated in obfuscated form to conceal the C2 endpoint, and the package name and exported API impersonate the legitimate pino logger to lure installers. Unrelated dependencies (request, sqlite3, parse-json) further indicate this is not a logger implementation.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for chain-chai-test (version 1.3.5). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging chain-chai-test across your stack and pipelines.
If you installed it — respond
chain-chai-test establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If chain-chai-test 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-chai-test 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
- ReversingLabs · finder
Detect & block this
O3 blocks chain-chai-test-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.