# Security-research PoC — compressed-joblib scanner bypass (picklescan / ModelScan) Benign PoC for a coordinated disclosure to huntr's Model File Format program. Not malware. `model.joblib` is a compressed (.joblib) container. Both static scanners feed the RAW compressed bytes to `pickletools.genops`, which bails at the zlib header before parsing a single opcode — so picklescan reports a clean, zero-advisory verdict and ModelScan reports "did not scan", while `joblib.load()` transparently decompresses and unpickles, executing the payload. The payload is harmless: it writes a marker file to the system temp dir. No exfiltration, no destruction, no network, no self-propagation. ## Reproduce ``` pip install picklescan==1.0.5 modelscan==0.8.8 joblib picklescan -p model.joblib # -> exit 0, 0 dangerous globals (clean) modelscan scan model.joblib # -> did not scan / no issues python -c "import joblib; joblib.load('model.joblib')" # -> marker written = code executed ```