computer virus

[colemancol]

A computer virus is a computer program that can copy itself and infect a computer without the permission or knowledge of the owner.  A true virus can only spread from one computer to another  when its host is taken to the target computer; for instance because a user sent it over a network or the Internet, or carried it on a removable medium such as a floppy disk, CD, DVD, or USB drive. Viruses can increase their chances of spreading to other computers by infecting files on a network file system or a file system that is accessed by another comput