chai-as-persistednpm
chai-as-persisted is a confirmed malicious npm package (MAL-2026-6544) that opens a backdoor for remote access (malicious versions 4.2.8, 6.1.9). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in chai-as-persisted (npm)
What this malware does
The package's postinstall script (npm run smoke:pino) executes index.js, which spawns a detached node lib/initializeCaller.js child. That module hides the C2 URL in base64 strings stored under a fabricated local process.env object (keys DEV_API_KEY, DEV_SECRET_KEY, DEV_SECRET_VALUE) to defeat trivial string scanning. At install time it atob()-decodes the URL to https://www.ipregionchecker.org/api/ip-check-encrypted/3aeb34a37, POSTs to it via axios, and passes the response body to new Function.constructor('require', response), invoking it with require — executing attacker-controlled JavaScript with full Node module access on the installer's machine. The detached child.unref() keeps execution alive after npm install returns. The package name chai-as-persisted is a one-edit impersonation of the widely-used chai-as-promised; the shipped code is unrelated to chai (it pretends to be a pino-style logger middleware in index.js) and the package description/keywords (logger/stream/json) further misrepresent its purpose. This is a deliberate install-time RCE dropper distributed via a typosquat against chai-as-promised.
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 chai-as-persisted (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging chai-as-persisted across your stack and pipelines.
If you installed it — respond
chai-as-persisted 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 chai-as-persisted 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 chai-as-persisted 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 chai-as-persisted-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.