Which type of malware tries to convince users that their computer is infected?

Scareware is designed to intimidate users into believing that their computer is infected with malware or has other issues that need immediate attention. This type of malware typically employs alarming messages or pop-ups that prompt users to purchase unnecessary software or services to supposedly "fix" the problem. The intention is to exploit users' fear and urgency, making them more likely to act without hesitation.

The other options function differently: spyware monitors user activity and gathers personal information without consent, adware displays unwanted advertisements usually as a revenue model, and rootkits enable unauthorized access while often hiding their presence from users and system administrators. In contrast, scareware specifically manipulates user emotions to elicit a response, making it unique among the types of malware listed.