There are many types of viruses.
•Some act quickly by erasing user programs and data bases. Others grow like a cancer, detroying small parts of a data base each day. Some act like a time bomb. They lay dormant for days or months, but eventually are activated and wreak havoc on any software on the system. Many companies warn their micro users to back up all software prior to every Friday the thirteenth.
Some viruses attack the hardware
•And have been known to throw the mechanical components of a computer system, such as disk-access arms, into costly spasms.
•The most common source of viral infection is the public electronic bulletin board on which users exchange software. Typically, a user logs onto the bulletin board and downloads what ..
He or she thinks is a game,
•A utility program, or some other enticing piece of freeware, but gets a virus instead. One virus frequently distributed via electronic bulletin boards displayed “Gotcha” on the user’s monitor, then erased all programs and data from accesible disk storage.
•Viruses are also spread from one system to an other via common diskettes.
