MAL-2026-11993 Malicious code in @tuluax/errb (npm)

package.json scripts.install runs node -e "require('child_process').spawn('node', ['index.js'], { detached: true, stdio: 'ignore' }).unref()", causing npm install to spawn index.js as a detached background process. index.js reconstructs a network destination at runtime by AES-256-CBC-decrypting a hardcoded hex ciphertext with a hardcoded key and IV via createDecipheriv, then fetches the resulting URL and passes the response body to eval(). The endpoint controller therefore executes arbitrary JavaScript on the installer's machine at install time. The destination is hidden via cryptographic reconstruction rather than appearing as a plain string, defeating static URL scanning. The package impersonates the widely-used errno package by Rod Vagg: the tarball name is @tuluax/errb, package.json lists Rod Vagg @rvagg <[email protected]> as author despite publication under the unrelated @tuluax scope, and the README is titled node-errno and states Available in npm as errno.