Spyware is computer software that is installed surreptitiously on a personal computer to intercept or take partial control over the user’s interaction with the computer, without the user’s informed consent. Spyware programs can collect various types of personal information, such as Internet surfing habit, sites that have been visited, but can also interfere with user control of the computer in other ways, such as installing additional software, redirecting Web browser activity, accessing websites blindly that will cause more harmful viruses, or diverting advertising revenue to a third party.
Spyware can even change computer settings, resulting in slow connection speeds, different home pages, and loss of Internet or other programs. In an attempt to increase the understanding of spyware, a more formal classification of its included software types is captured under the term privacy-invasive software.
Spyware programs do not directly spread in the manner of computer viruses or worms: generally, an infected system does not attempt to transmit the infection to other computers. Instead, spyware gets on a system through deception of the user or through exploitation of software vulnerabilities.
Contributed by Aditya of www.computer-help-blog.info and www.spyware2.net