Computer virus is a procedure that can change or damage data stored in computers, and it can constantly duplicate itself during its operation and thus cause damage.
Computer virus widely spread in the United States in 1987, and the first computer virus "Small Ball" spread to our country by the end of that year. Since then, imported and domestic virus has been discovered. By now, computer virus has multiplied to more than 20, 000varieties; over 90% of them can attack microcomputers.
1. Features of Computer Virus
(1) Basic features
(a) Infection. Computer virus as a procedure can duplicate itself to other normal procedures or on some components of the system, for example, leading portion of disk. This is the basic feature of virus procedure. As computer network develops increasingly and extensively, computer virus can spread extensively through Internet within short time.
