VIRUS
- A virus is a small piece of software that piggybacks on real programs.
- Infect other programs by modifying them.
- For example, a virus might attach itself to a program such as a spreadsheet program. Each time the spreadsheet program runs, the virus runs, too, and it has the chance to reproduce (by attaching to other programs) or wreak havoc.
- Computer viruses are called viruses because they share some of the traits of biological viruses.
- First one written in 1983 by USC student Fred Cohen to demonstrate the concept.