Computer Virus

Computer viruses are software programs that invade a computer system to wreck havoc with computer files or the computer users themselves. Some are benign causing nothing more than a nuisance while others can delete files or even destroy computer hardware. Typically viruses are programmed to reproduce themselves and spread from one computer system to another, just like a normal human virus spreads via human contact throughout the population. Computer viruses can be spread via diskettes or other removable media, by way of email attachments, or in some cases simply by being connected to the Internet and not protected.

Article from PCHELL