Which malware program looks useful but is malicious?

• A. Trojan Horse
• B. Virus
• C. Worm
• D. Spyware

Answer: (A)

Deception through masquerading as legitimate software is the hallmark trait. A Trojan Horse looks useful—like a legitimate program, game, or utility—but actually carries a malicious payload once installed. Its goal is to trick the user into running it, which then grants an attacker backdoor access, steals data, or delivers additional malware. The key idea is that the harmful action is concealed behind a façade of usefulness, which distinguishes it from other malware types. A virus attaches to a host program and spreads with those files; a worm propagates across networks without needing user action; spyware quietly gathers information about the user, often with stealthy behavior but not necessarily posing as something beneficial. So the Trojan Horse best fits the description of "looks useful but is malicious."