Computer virus may be defined as a small software
programme which has the capability of reproducing itself which may result in
significant harm to files and/or programmes on the same computer. It is said
that true computer virus only spread to another computer with the aid of human
assistance. This is so because human has to write the virus programme and set
up the various ways in which the programme can be spread. There is no standard
size of the virus file, but it may range between 1-300 Kb. These computer
viruses may begin by having a negative effect on the programme causing it to
run incorrectly or corrupt the memory of the computer. These two scenarios can
eventually lead to crashing of the computer’s hard drive.
No
one wants his/her computer to be infected with virus. Because of this some people
will invest a lot of time researching the various types of computer virus and the
security threat that is related to each type. This reach is done in order to find
out the nature of the virus such as how the virus is programmed, ways in which
the virus carry out the damage to the hard drive and very importantly the
methods by which they are spread.
Virus
will attack various sections computer system such as the boot sector, the
browser, various files among other areas.
Examples of some computer viruses
are:
- Actifed - this virus infects .COM and .EXE files.
- AGENA - this virus resides in the memory infecting .COM and .EXE files
- Ada - This virus can infect any of the DOS operating system