MAL-2026-13719 Malicious code in commonjs-assertion (npm)

Package presents itself as a chai-like assertion library. index.js uses hex-encoded strings to hide the identifiers 'child_process' and 'node' and, on require, unconditionally invokes child_process.spawn to launch a detached, stdio-ignored node child running lib/chai/utils/assertion.js. That file is a heavily obfuscated loader (obfuscator.io rotated string array plus a custom base64/URI decoder) whose decoded logic performs an HTTP GET to a URL reconstructed from the encoded string array and passes the response body to new Function(…, body)(require), granting the fetched remote code full Node access. The assertion.js file is not referenced by chai's real code and is only reachable via the hex-hidden spawn in index.js. Importing the package causes remote code execution on the installer's host at load time.

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.