Antivirus are small software programs that hopefully will spread from one computer to a new and to interfere by using computer operation.
A contamination might.. corrupt or delete data on your computer, use your e-mail program to spread itself to be able to other computers, or even erase everything on your hard disk.
Antivirus are often spread as a result of attachments in e-mail email or instant messaging information. That is why it is necessary that you never open e-mail attachments until you know who it’s from also, you are expecting it.