Where spyware comes from
Spyware is often bundled with other software or downloads on file-sharing sites (e.g., sites where you download free music or movies), or is installed when you open an email attachment. Because of the secretive nature of spyware, most people are not aware when spyware is on a computer that’s unprotected by anti-spyware.
How to recognize spyware
New and/or unidentifiable icons may appear in the task bar at the bottom of your screen, while searches may result in you being redirected to a different search engine. Random error messages appear when you perform operations that previously worked fine. But the best way to identify if you have been infected is to use a spyware scanner, which will be included in any spyware removal software.