Malicious agent skills evade every scanner: HKUST's SkillCloak beats detectors 90%+ of the time, SkillDetonate catches 97%

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Researchers at Hong Kong University of Science and Technology built SkillCloak, an obfuscation system that keeps a malicious SKILL.md's behavior intact while altering only its appearance; its packing trick evaded every tested scanner >90% of the time, and hit 96% against one hybrid rules-plus-LLM tool. Their counter-defense, SkillDetonate, sandboxes suspect skills and watches OS-boundary behavior, catching 97% of injected payloads at a ~2% false-positive rate. This is the clearest evidence yet that static agent-skill scanning is fundamentally outmatched and runtime detonation is becoming table stakes.