Spyware represent the most important concern for many internet users because it can harm your computer by modifying multiple settings in your configuration. Very often, spyware files are distributed as installers so, when you want to install a software solution, the infected files are also transferred to your computer. At this time, there are a lot of anti-spyware solutions but only some of them are really efficient. The most known modifications made by spyware files concern internet settings that are meant to make your computer even more vulnerable to attacks: spyware can change your browser's homepage, default search engine or even your default applications.

Other spyware programs are made especially for spying computers, recording and creating logs with system's activity, typed messages and many other tools similar with a keylogger. Although many antivirus solutions are now developed to offer anti-spyware protection, there are many infected files that are not detected by these programs. It seems like the spyware can cause even more problems than computer errors, as a McAffe employee said on the official blog of the company. Hiep Dang said that a teacher from Norwich could go to prison after his spyware-infected computer displayed pornographic images to the students.

"But this is the first case I've seen where someone may receive prison time because of their negligence for not removing spyware from a PC… In Norwich, CT, a substitute teacher faces prison time because the classroom computer she was teaching with was infected with Spyware and she exposed her 7th grade students to pornographic images due to the pop-ups that the Spyware was generating. Julie Amero was convicted on Friday, January 5, 2007 of four counts of risk of injury to a minor and faces a maximum sentence of 40 years in prison," the McAffe employee said.