Virus

A type of malicious software that can destroy the computer’s hard drive, files, and programs in memory, and that replicates itself to other disks. Selfreplicating, malicious code that attaches itself to an application program or other executable system component and leaves no obvious signs of its presence. The oldest form of malicious code objects that plague cyberspace. Once they are in a system, they attach themselves to legitimate operating system and user files and applications