'Shādú' literally means 'to kill poison'—'shā' (kill) and 'dú' (poison, toxin, or virus)—and is the standard Chinese term for antivirus software. Though it sounds violent, it’s a common, neutral technical compound used in computing contexts to refer to programs designed to detect, block, and remove malicious software like viruses, worms, and trojans.

The word reflects a metaphorical extension of 'poison' to digital threats: just as poison harms the body, malware harms computer systems. It appears in product names (e.g., 360杀毒), system notifications, and everyday tech discussions. Unlike English 'antivirus', which emphasizes prevention, 杀毒 emphasizes active removal—hence its strong verb-based root—but functions grammatically as a noun in modern usage (e.g., 'install antivirus'). It’s rarely used outside computing; you wouldn’t say it for biological toxins or medical treatment.