Antivirus are small software programs that should spread from one computer to another and to interfere with computer operation.
A viral might.. corrupt or delete data on your desktop, use your e-mail application to spread itself to help other computers, or even erase everything onto your hard disk.
Antivirus are often spread by attachments in e-mail information or instant messaging emails. That is why it is necessary that you never open e-mail attachments should you not know who it’s from and you are expecting it.