How did computer virus originate?

Answer 1

There are different types of viruses. Some of the prominent ones are Trojan horses , worms, and email viruses. The Trojan horses are computer programs which pretend to do one thing but actually do damage when they start it. The worms viruses are pieces of software that use computer networks and security flaws to create copies of itself. A cop y of the worm will then scan the network for any other machine that has a specific security flaw, and then replicate itself to the new machine. With regards to email viruses, these use email messages, and usually will copy and automatically mail itself to hundreds of people.

There are two generalities of viruses, including resident and nonresident viruses. Resident viruses are those viruses that contain a specific replication module which is alarmingly similar to t hose employed by nonresident viruses. A resident virus is one that stays in memory after it executes, and even after its host program is executed. Resident viruses are often subdivided into categories like fast infectors, and slow infectors. Fast infectors are those particular viruses which are designed to affect as many files as possible and slow infectors are designed to infect hosts infrequently. For instance some slow infectors will only infect files when they are copied.

Nonresident viruses on the other hand are those viru ses which consist of a finder module and a replication module. The finder module is responsible for finding new files to infect, while the replication module is the component that actually infects the found files