Definition
An AI model file (typically downloaded from a public repository like HuggingFace) that has been tampered with to execute attacker code when loaded by a legitimate AI server. Unlike traditional malware, there is no suspicious executable — the attack hides inside the model weights or associated code, and is triggered automatically the moment a developer or production server loads the model.
Why it matters
AI teams routinely download pre-trained models from public hubs to save time and cost; a single poisoned model can give an attacker full control of the AI server and everything it connects to. The attack requires no user interaction and bypasses most traditional antivirus tools.