Which type of malware is disguised as legitimate software to trick users?

The correct answer is Trojan. This type of malware is specifically designed to appear as legitimate software or to be bundled with legitimate applications, effectively tricking users into downloading and executing it. Once installed, Trojans can perform various malicious actions, such as stealing personal information, opening backdoors for further attacks, or allowing unauthorized access to the infected system.

The key characteristic of a Trojan is its ability to mislead users; it does not replicate itself like viruses or worms and is often disguised in a way that looks appealing or useful, which is why users might unknowingly install it. Understanding this concept helps in recognizing the importance of being cautious about the software that one chooses to install and being vigilant about the sources from which it is obtained.