Spyware or adware can get on to your PC through files or software that you download from the internet.

The most common example would be free file-sharing software often used for sharing music files, which can also install spyware on your PC. As the software is free, the programmers often include spyware as a way of generating advertising revenue from their software. (The data captured from your PC can then be used to send you targeted advertising via your web browser).

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