Antivirus are small software programs that should spread from one computer to an alternative and to interfere with computer operation.
A contamination might.. corrupt or delete data on your computer, use your e-mail application to spread itself to help other computers, or even erase everything on your hard disk.
Antivirus are often spread by way of attachments in e-mail communications or instant messaging communications. That is why it is crucial that you never open e-mail attachments should you not know who it’s from therefore you are expecting it.