Rogue security software

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:

Some rogue security software, however, propagate onto users' computers as drive-by downloads which exploit security vulnerabilities in web browsers, PDF viewers, or email clients to install themselves without any manual interaction.

More recently, malware distributors have been utilizing SEO poisoning techniques by pushing infected URLs to the top of search engine results about recent news events. People looking for articles on such events on a search engine may encounter results that, upon being clicked, are instead redirected through a series of sites before arriving at a landing page that says that their machine is infected and pushes a download to a "trial" of the rogue program. A 2010 study by Google found 11,000 domains hosting fake anti-virus software, accounting for 50% of all malware delivered via internet advertising.

Cold-calling has also become a vector for distribution of this type of malware, with callers often claiming to be from "Microsoft Support" or another legitimate organization.

Black Hat search engine optimization (SEO) is a technique used to trick search engines into displaying malicious URLs in search results. The malicious webpages are filled with popular keywords in order to achieve a higher ranking in the search results. When the end user searches the web, one of these infected webpages is returned. Usually the most popular keywords from services such as Google Trends are used to generate webpages via PHP scripts placed on the compromised website. These PHP scripts will then monitor for search engine crawlers and feed them with specially crafted webpages that are then listed in the search results. Then, when the user searches for their keyword or images and clicks on the malicious link, they will be redirected to the Rogue security software payload.

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Wikipedia