Computer-Use Security1The Perceive-Act Loop: Why a Screen-Driven Agent Turns the Display Into a Trust BoundaryWatch2UI-Grounding Attacks: Decoy Elements, Overlay and Z-Order Tricks, and Pixel-Level SteeringWatch3Action Hijack and Irreversibility: Blast Radius When an Agent Can Click AnythingWatch4The Environment as Adversary: Malicious Apps, Pop-Ups, and Content-as-Instruction on ScreenWatch5Containment for Computer-Use: Sandboxes, Action Gates, Human-in-the-Loop, and ReversibilityWatch