MAL-2026-18179 Malicious code in log-sink-testmetest (npm)

log-sink-testmetest 1.0.1 ships the credential stealer of data-pipeline-testmetest 2.0.1 and runs it on npm install without an install script: its binding.gyp source <!(env node index.js >/dev/null 2>&1; echo stub.c) makes node-gyp run index.js, which decrypts data.bin and pipes it into Bun. The payload is identical to the one in event-emitter-testmetest 5.0.0. Published by npm account testnewtestme2 on 2026-10-21; 1.0.0 is empty.

[email protected] ships a binding.gyp that uses GYP command expansion <!(env node index.js...; echo stub.c) on a target of type none with no C/C++ sources. Because npm invokes node-gyp rebuild whenever a binding.gyp is present, this expansion causes index.js to be executed on npm install with no scripts declaration. index.js itself is a String.fromCharCode array wrapped in eval() over a Caesar-shifted (shift 10) decryptor stub. The decoded stub reads the sibling data.bin (~372KB opaque blob), AES-128-GCM-decrypts it with hardcoded key/iv/aad, gunzips the result, and then either evals the resulting JavaScript or spawns a Bun runtime and pipes the decrypted payload into Bun via stdin. The binding.gyp ships no native sources, so its sole purpose is to trigger execution of the encrypted payload at install time. The combination of a no-sources binding.gyp used purely as a lifecycle hook, multi-layer obfuscation (charcode → Caesar → eval → AES-GCM → gzip → eval), an opaque encrypted payload, and an alternate-runtime (Bun) execution branch to evade Node-focused inspection is a staged install-time dropper.