Scareware comprises several classes of scam software with malicious payloads, or of limited or no benefit, that are sold to consumers via certain unethical marketing practices. The selling approach uses social engineering to cause shock, anxiety, or the perception of a threat, generally directed at an unsuspecting user.
Some forms of spyware and adware also use scareware tactics.
Scareware and Fake Antivirus
A tactic frequently used by criminals involves convincing users that a virus has infected their computer, then suggesting that they download (and pay for) fake antivirus software to remove it.
Usually the virus is entirely fictional and the software is non-functional or malware itself.
According to the Anti-Phishing Working Group (APWG), the number of scareware packages in circulation rose from 2,850 to 9,287 in the second half of 2008. In the first half of 2009, the APWG identified a 583% increase in scareware programs.
The "scareware" label can also apply to any application or virus (not necessarily sold as above) which pranks users with intent to cause anxiety or panic.
Scareware: Software that Scams its Users
Internet Security bloggers / writers also use the term "scareware" to describe software products that -- while serving some desired purpose -- also produce a lot of frivolous and alarming warnings or threat notices, most typically commercial firewall and registry cleaner software.
This class of program tries to increase its perceived value by bombarding the user with constant warning messages that do not increase its effectiveness in any way. Software is packaged with a look and feel that mimics legitimate security software in order to deceive consumers.
Some websites display pop-up advertisement windows or banners with text such as: "Your computer may be infected with harmful spyware programs. Immediate removal may be required. To scan, click 'Yes' below." These websites can go as far as saying that a user's job, career, or marriage would be at risk.
Products using advertisements such as these are often considered scareware. Serious scareware applications qualify as rogue software.
Scareware as Spyware
Some forms of spyware also qualify as scareware because they change the user's desktop background, install icons in the computer's notification area (under Microsoft Windows), and generally make a nuisance of themselves, claiming that some kind of spyware has infected the user's computer and that the scareware application will help to remove the infection.
In some cases, scareware trojans have replaced the desktop of the victim with large, yellow text reading "Warning! You have spyware!" or a box containing similar text, and have even forced the screensaver to change to "bugs" crawling across the screen.
Uninstallation of Security Software
Another approach is to trick users into uninstalling legitimate antivirus software.
This document is licensed under the GNU Free Documentation License (GFDL), which means that you can copy and modify it as long as the entire work (including additions) remains under this license.
Free eBook: The Windows 7 Guide: From Newbies to Pros. In this 46 page guide you will be introduced to Windows 7 and what it has to offer. It will teach you about the new taskbar, how to resolve software compatibility issues, how to customize Windows Aero, and explain what the Windows 7 Libraries are all about. Also included: a detailed list of what software is included in Windows 7, and how easy networking is with Windows 7 along with other topics. The advice within this guide will help new users become acquainted with Windows 7 and can also help those who are on the fence about purchasing Windows 7 decide if it would be a good idea. Click here to download this eBook now! Note: this eBook is free, but registration is required; after that, you can select more ebooks and videos for download without registering again. If you have questions / problems with the registration form, please read this.