What is a main cause of a virus on a computer

The main cause of computer viruses is putting an infected USB flash drive into your computer, opening an infected email, going to websites that are dangerous, and downloading infected files Some viruses disguising them self's as pop-ups. Files that could have downloaded themselves while you are on theses dangerous websites are viruses as well.
Be carful and make sure you don't do anything to deal with these! ;)

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