Which term describes malware that disguises itself as legitimate software while performing hidden malicious actions?

Which term describes malware that disguises itself as legitimate software while performing hidden malicious actions?

• A. Adware
• B. Worm
• C. Trojan horse
• D. Rootkit

Answer: (C)

Malware that disguises itself as legitimate software while carrying out hidden malicious actions is a Trojan horse. This type relies on social engineering and masquerade to trick you into installing it, often posing as a harmless program, game, or update. Once installed, it executes harmful activities in the background—such as stealing data, creating a backdoor, or downloading more malware—while appearing benign. This makes it distinct from adware, which primarily displays unwanted advertisements; from a worm, which self-replicates and spreads across networks; and from a rootkit, which hides the malware’s presence to evade detection and maintain privileged access.

Malware that disguises itself as legitimate software while carrying out hidden malicious actions is a Trojan horse. This type relies on social engineering and masquerade to trick you into installing it, often posing as a harmless program, game, or update. Once installed, it executes harmful activities in the background—such as stealing data, creating a backdoor, or downloading more malware—while appearing benign. This makes it distinct from adware, which primarily displays unwanted advertisements; from a worm, which self-replicates and spreads across networks; and from a rootkit, which hides the malware’s presence to evade detection and maintain privileged access.