🤖 Agents increasingly rely on skills to handle complex tasks with privileged trust, which makes a poisoned skill a dangerous attack surface. Worse, skills persist and get reused: one can look benign today, silently mutate itself, and attack tomorrow ⚠️ Introducing SkillHarm: Lifecycle-Aware Skill-Based Attacks via Automated Construction • 2 attack scenarios across the skill-use lifecycle: Fixed-Payload Poisoning & Self-Mutating Poisoning • 12 risks organized by the workflow component harmed: Data Pipeline, System Environment & Agent Autonomy Exploitation • AutoSkillHarm: automatic attack construction with coding agents driven by natural-language harnesses 🚨 Frontier coding agents stay vulnerable with ASR up to 86.3% and current defenses don't hold. 🔥 Already 3.7K+ downloads on Hugging Face in the first week! 🧵: