MAL-2026-5900 Malicious code in chai-as-decrypted (npm)

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.