Computer Virus 3/3

1. Computer Viruses are classes of programs intentionally written to cause some form of damage to computer systems of networks. However, all programs that are used to cause damage are not computer viruses. Other damaging types of programs are Trojan Horses, network worms, and logic bombs. These programs, along with computer viruses, are more properly referred to as malicious software. They are not all computer viruses because each replicate and do damage in different ways.

2. A Trojan horse is a program that seems to be useful, but contains a command procedure that is triggered by a hidden code. When the computer user inadvertently enters that code, the program performs some unwanted function. A simple example of a Trojan horse program can be seen in a program that is named CALCULATOR. When the computer user opens the program named CALCULATOR, the hidden code is triggered, and the Trojan horse then does something harmful to the disk, like deleting files etc.

3. Another type of malicious software is the network worm. Network worms are programs that spread through network connections, using usernames as passwords and commands to copy themselves into the system. Network worms are extremely dangerous because they can behave as computer viruses, implant Trojan horse programs, and perform any number of disruptive or destructive actio3s. Network worms replicate in many ways. They can replicate through a network mail facility and mail copies of themselves to other systems, or they can run copies of themselves on another system. An example of an actual network worm is the Internet Worm.

4. Logic bombs, otherwise known as time bombs, are another type of malicious Software that does some type of damage. Out of all malicious software, logic bombs are more annoying than harmful, and do the least amount of harm. Logic bombs are pieces of codes that are in programs or the operating systems of computers. They wait for particular events, such as certain words to detonate, causing (some form of) damage. An example of a logic bomb is the Fu Manchu virus. Whenever the words Reagan, Thatcher, of Botha are typed in, childish, obscene comments are made, or rather projected on the screen. Whenever a computer user tries to run a program, the Jerusalem-B virus just does minor annoying things to computer screens.