Computer Viruses
A computer virus is an illegal and potentially
damaging computer program
designed to infect other software by attaching
itself to any software it
contacts. In many cases, virus programs are
designed to damage computer systems
maliciously by destroying or corrupting
data. If the infected software is
transferred to or accessed by another
computer system, the virus spreads to the
other system. Viruses have become a
serious problem in recent years, and
currently, thousands of known virus
programs exist (Reed 85-102). Three types of
viruses are a boot sector
viruses, file virus, and Trojan horse virus. A boot
sector virus infects the
boot program used to start the system. When the
infected boot program
executes, the virus is loaded into the computer’s
memory. Once a virus is in
memory, it can spread to any floppy disk inserted
into the computer. A file
virus inserts virus code into program files. The virus
then spreads to any
program that accesses the infected file. A Trojan horse
virus (named after
the Greek myth) hides within or is designed to look like a
legitimate
program. Some viruses interrupt processing by freezing a computer
system
temporarily and then displaying sounds or messages. Other viruses
contain
time bombs or logic bombs. A time bomb is a program that performs an
activity on
a particular date. A logic bomb is a program that performs an
activity when a
certain action occurs, such as an employee being terminated.
A worm, which is
similar to a virus, copies itself repeatedly until no memory
or disk space
remains. To detect computer viruses, antivirus programs have
been developed.
Besides the detecting of the viruses, antivirus programs
also have utilities to
remove or repair infected programs or files. Some
damaged files cannot be
repaired and must be replaced with uninfected backup
files. The table below
outlines some techniques used to protect computer
systems. Table Techniques for
Virus Protection and System Backup Using
Virus Protection Software Backing Up
Your System Install virus protection
software on every computer system. Develop
a regular plan for copying and
storing important data and program files. Before
use, scan every floppy disk
with a virus scan program to check for viruses.
Implement a backup plan
and adhere to its guidelines. Check all programs
downloaded from the Internet
or bulletin boards for viruses. Keep backup copies
of files in fireproof
safes or vaults or off-site If your system becomes virus
infected and you
have questions, contact the National Computer Security
Association (NCSA)
for low-cost assistance (Elmhurst, 6 Nov.
1998).
Bibliography
Chambers, Anita R., and Zachary W. Peters.
"Protecting Against Virus
Attacks." Computers May 1998: 45-62. Elmhurst,
Mark. "Virus Infection: Where
to Obtain Assistance" Word 97, Project 3.
http://www.scsite.com/wd97/pr3.htm
(6 Nov. 1998). Reed, Margaret E. An
Introduction to Using Computers. Chicago:
West Davidson Jones Publishing
Company , 1998.