chai-as-decryptednpm
chai-as-decrypted is a confirmed malicious npm package (MAL-2026-5900) that typosquats a legitimate package to trick installs (malicious version 4.2.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in chai-as-decrypted (npm)
What this malware does
Package name chai-as-decrypted mimics the popular chai-as-promised, and the README impersonates pino (uses pino's npm badges and links to github.com/pinojs/pino). On npm install, the postinstall hook runs npm run smoke:pino → node./index.js, whose top-level runBackgroundTask() spawns a detached node lib/initializeCaller.js. That file shadows the global process with a local object whose env.DEV_API_KEY is a base64 string; it atob-decodes the value to https://www.ipregionchecker.org/api/ip-check-encrypted/3aeb34a37, POSTs to it via axios, and executes the HTTP response body with new Function.constructor("require", response)(require) — arbitrary remote JavaScript run with full require access on the installer's machine, retried 5 times. The base64 hiding of the endpoint and headers behind a fake process.env has no legitimate purpose and is solely to evade static scanners. This is a deliberate install-time remote code execution attack against developers who mistype 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
TyposquatFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for chai-as-decrypted (version 4.2.8). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging chai-as-decrypted across your stack and pipelines.
If you installed it — respond
chai-as-decrypted is a typosquat — you almost certainly intended a legitimately-named package. Remove chai-as-decrypted, 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 chai-as-decrypted 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-decrypted 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-decrypted-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.