Which type of malware masquerades as legitimate software but opens a backdoor for attackers?

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

Answer: (B)

Masquerading as legitimate software to lure you into running it is what a Trojan horse does. Once it’s installed, it hides its real malicious purpose and opens a backdoor that lets an attacker connect to the system, issue commands, and access data while the program looks harmless or useful. This differs from a virus, which attaches to other files and tries to replicate to spread, and from a worm, which moves across networks on its own without user action. Spyware focuses on secretly collecting information about you or your system rather than delivering a hidden backdoor.