It is programmed to attack in response to a particular event or sequence of events. For example, a programmer for a firm might plant logic bombs files for his work and program them to go off if he s ever fired. If a logic bomb is ever uses a certain time to activate it s detonation, then it is called a time bomb. Software viruses spread from program to program just like a virus spreads through a body. Vaccine programs are designed to search for viruses and notify the user when they re found, and remove them from infected disks or files.
Worms are like viruses in the sense that they are a parasite off computers.
The difference between Viruses and worms is that worms travel through networks independently. Simply simply shutting down all the computers in the network can eliminate it. These sabotage programs have become a major concern along with electronic trespassing. I used to always leave my computer on and connected to the Internet. One night I was going to start downloading a few mp3 files and go to bed when I noticed another faint cursor on my screen.