Scareware is a form of malware which uses social engineering to cause shock, anxiety, or the perception of a threat in order to manipulate users into buying unwanted software[1] (or products). Scareware is part of a class of malicious software that includes rogue security software, ransomware and other scam software that tricks users into believing their computer is infected with a virus, then suggests that they download and pay for fake antivirus software to remove it.[2] Usually the virus is fictional and the software is non-functional or malware itself.[3] According to the Anti-Phishing Working Group, the number of scareware packages in circulation rose from 2,850 to 9,287 in the second half of 2008.[4] In the first half of 2009, the APWG identified a 585% increase in scareware programs.[5]
The "scareware" label can also apply to any application or virus which pranks users with intent to cause anxiety or panic.