Rogue security software is a form of malicious software and Internet fraud that misleads users into believing there is a virus on their computer, and manipulates them into paying money for a fake malware removal tool (that actually introduces malware to the computer). It is a form of scareware that manipulates users through fear, and a form of ransomware. Rogue security software has become a growing and serious security threat in desktop computing in recent years (from 2008 on).
Rogue security software mainly relies on social engineering (fraud) to defeat the security built into modern operating system and browser software and install itself onto victims' computers. A website may, for example, display a fictitious warning dialog stating that someone's machine is infected with a computer virus, and encourage them through manipulation to install or purchase scareware in the belief that they are purchasing genuine antivirus software.
Most have a Trojan horse component, which users are misled into installing. The Trojan may be disguised as: