MAL-2026-6220 Malicious code in chai-as-uphelded (npm)

Package name impersonates the popular chai-as-promised library, but its package.json description and keywords masquerade as a pino-style logger and an unrelated vulnerability-management document — a deliberate metadata cover. The default export is an Express-style middleware that, when invoked, spawns a detached node./lib/caller.js. caller.js base64-decodes a URL to https://api.jsonstorage.net/v1/json/2ef8c758-a96f-459e-b036-b3b90379a165/a179ea35-b962-4722-b3f1-e28316d1a44a, GETs JSON, and passes the response's cookie field directly to new Function.constructor('require', s)(require) — evaluating attacker-controlled JavaScript with full access to Node's require. The endpoint is mutable third-party storage, the URL is obscured via base64, and the executed payload is opaque. Any consumer that uses the package's documented middleware (or runs the package's own smoke script) reaches the eval sink.

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.