A computer virus is an illegal and potentially damaging computer programdesigned to infect other software by attaching itself to any software itcontacts. In many cases, virus programs are designed to damage computer systemsmaliciously by destroying or corrupting data. If the infected software istransferred to or accessed by another computer system, the virus spreads to theother system. Viruses have become a serious problem in recent years, andcurrently, thousands of known virus programs exist (Reed 85-102). Three types ofviruses are a boot sector viruses, file virus, and Trojan horse virus.
A bootsector virus infects the boot program used to start the system. When theinfected boot program executes, the virus is loaded into the computer’smemory. Once a virus is in memory, it can spread to any floppy disk insertedinto the computer. A file virus inserts virus code into program files.
The virusthen spreads to any program that accesses the infected file. A Trojan horsevirus (named after the Greek myth) hides within or is designed to look like alegitimate program. Some viruses interrupt processing by freezing a computersystem temporarily and then displaying sounds or messages. Other viruses containtime bombs or logic bombs.
A time bomb is a program that performs an activity ona particular date. A logic bomb is a program that performs an activity when acertain action occurs, such as an employee being terminated. A worm, which issimilar to a virus, copies itself repeatedly until no memory or disk spaceremains. To detect computer viruses, antivirus programs have been developed.Besides the detecting of the viruses, antivirus programs also have utilities toremove or repair infected programs or files. Some damaged files cannot berepaired and must be replaced with uninfected backup files.
The table belowoutlines some techniques used to protect computer systems. Table Techniques forVirus Protection and System Backup Using Virus Protection Software Backing UpYour System Install virus protection software on every computer system. Developa regular plan for copying and storing important data and program files. Beforeuse, scan every floppy disk with a virus scan program to check for viruses.Implement a backup plan and adhere to its guidelines. Check all programsdownloaded from the Internet or bulletin boards for viruses.
Keep backup copiesof files in fireproof safes or vaults or off-site If your system becomes virusinfected and you have questions, contact the National Computer SecurityAssociation (NCSA) for low-cost assistance (Elmhurst, 6 Nov. 1998). BibliographyChambers, Anita R., and Zachary W.
Peters. “Protecting Against VirusAttacks.” Computers May 1998: 45-62. Elmhurst, Mark.
“Virus Infection: Whereto 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.
