07-05-2014, 04:13 PM
Computer Virus Fact Sheet
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What is a computer virus?
Computer viruses have impacted a significant number of computers
worldwide over the past few years. There are over 10,000 known computer
viruses. Over 200 new viruses are being discovered every month. A
computer virus is a (hidden) program, which invades your computer; much
like a biological virus invades a living cell. A computer virus contains code
that has the potential to cause damage and/or perform unwanted/unauthorized
functions.
How does a virus work?
A computer virus performs two basic functions: it copies itself from machine to machine (self-
reproducing), and it executes the instructions the perpetrator has planned.
A computer virus exhibits three characteristics: a replication mechanism, an activation mechanism, and
an objective. The replication mechanism searches for other programs to infect, if it finds any, it inserts the
hidden instructions in the program then it modifies the execution sequence of the program's instructions
such that the hidden code will be executed whenever the program is invoked. The activation mechanism
checks for the occurrence of some event. When the event occurs, the computer virus executes its
objective.