A warning message that pops up on screen claiming the user's computer is currently contaminated or not running properly. Also called "fake antivirus" and "rogue antivirus," scareware is a dishonest attempt to cause a user to purchase antivirus, a registry cleaner or some other software that repairs problems.
Worse yet, scareware may be used to entice the user to install phony software that implants a real virus or some other malware. In either case, the dire warning often frightens people into taking action. See
ransomware,
spyware and
wares.