A computer virus is an illegal and potentially damaging computer program designed to infect othersoftware by attaching itself to any software it contacts. In many cases, virus programs are designed todamage computer systems maliciously by destroying or corrupting data. If the infected software istransferred to or accessed by another computer system, the virus spreads to the other system. Viruses havebecome a serious problem in recent years, and currently, thousands of known virus programs exist (Reed85-102).
Three types of viruses are boot sector virus, file virus, and Trojan horse virus. A boot sector virusinfects the boot program used to start the system. When the infected boot program executes, the virus isloaded into the computers memory. Once a virus is in a memory, it can spread to any floppy disk insertedinto the computer. A file virus inserts virus code into program files. The virus then spreads to any programthat accesses the infected file.
A Trojan horse virus (named after a Greek myth) hides within or is designedto look like a legitimate program. Some viruses interrupt processing by freezing a computer system temporarily and then displayingsounds or messages. Other viruses contain time bombs or logic bombs. A time bomb is a program thatperforms an activity on a 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 is similar to a virus, copiesitself repeatedly until no memory or disc space remains. To detect computer viruses, antivirus programs have been developed. Besides detecting viruses,antivirus programs also have utilities to remove or repair infected programs and files. Some damaged filescannot be repaired and must be replaced with uninfected backup files.
The table below outlines sometechniques used to protect computer systems. TableTechniques for Virus Protection and System BackupUsing Virus Protection SoftwareBacking up Your SystemInstall virus protection software on every computer system. Develop a regular plan for copying andstoring important data and program files. Before use, scan every floppy disk with a virus scan program to check for viruses. Implement abackup plan and adhere to its guidelines.
Check all programs downloaded from the Internet or bulletin boards for viruses. Keep backup copies offiles in fireproof safes or vaults off-site. If your system becomes virus infected and you have questions, contact the National Computer SecurityAssociation (NCSA) for low-cost assistance (Elmhurst, 6 Nov. 1998). Works CitedChambers, Anita R.
, and Zachary W. Peters. “Protecting Against Virus Attacks. “Computers May1998: 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 JonesPublishing Company, 1998.
