A computer virus is a program that requires a host in order to make copies of itself on computer disks. Viruses may infect (copy to, and spread from), program files, programs in disk sectors, and files that use macros. The ability to self-replicate distinguishes viruses from programs that do not, and this parasitic nature is neither an accident, nor a computer glitch. All viruses are created by people who know how to write computer programs.

The threat:

• Requires a host computer in order to make copies of itself on computer disks
• Infects (copy to, and spread from) program files
• Self-replicates
• Created by people who know how to write computer programs

Refer to our recommended practices and instructions for removing infections for more information.