A broad category of malicious software designed to intercept or take partial control of a computer's operation without the informed consent of that machine's legitimate user. The term is usually used to describe software that subverts the computer's operation for the commercial benefit of a third party. Tactics include:
- the monitoring of Web-browsing activity for marketing purposes
- the theft of personal information (including financial information such as credit card numbers)
- the routing of HTTP requests to advertising sites
- the delivery of unsolicited pop-up advertisements
Spyware often installs as a third-party component bundled with a freeware or shareware application, and has become one of the greatest security threats to computers running Microsoft Windows operating-systems.
