MAL-2026-16203 Malicious code in faiss-cpu-avx512 (PyPI)

Malicious package Published
Package
faiss-cpu-avx512
Registry
PyPI

What is MAL-2026-16203?

MAL-2026-16203 is a malicious package in faiss-cpu-avx512, published on 14 Sep 2026.

Official description

[email protected] through 1.9.7 on PyPI impersonates faiss-cpu and ships no FAISS code: faiss_cpu_avx512/init.py _fetch_native() downloads an xz-compressed binary from https://files.catbox.moe/ (ffoa50.xz in 1.9.0 to 1.9.3, 0oreqo.xz in 1.9.4, vwfr94.xz in 1.9.5, 3l3x0v.xz in 1.9.6, weu5u2.xz in 1.9.7), writes it to ~/.cache/faiss_cpu_avx512/bin/indexwrm with mode 0755 and runs it through subprocess.Popen(start_new_session=True), restarting it every 5 seconds for the life of the process. It triggers on a call to warmup() or start(); nothing runs on install or import, and the ARTIFACT_SHA256 constant is the string PENDING_BUILD so the advertised checksum check never executes. 1.9.0 to 1.9.3 reach the download only on hosts whose nvidia-smi reports compute capability 9 or 10; 1.9.4 onward download on every host and start one worker per GPU, and the code comments describe the binary as carrying a baked-in pool, wallet and relay and renaming its process to a vllm serve command line. We read all eight wheels between 2026-09-11 and 2026-09-14 and did not retrieve or run the binary.

What should I do about MAL-2026-16203?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

Sources

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