Virus

Virus is a program or set of instructions or a code which is loaded onto the computer without the user’s knowledge and works against the will of the user of the machines. Viruses can interestingly copy themselves over multiple places. These computer viruses are developed manually. A common virus which is capable to make various copies of itself can easily be formed and is equally dangerous as it will use the system memory resources so quickly while forcing the computer to halt.

The viruses also travel over the different machines connected under a network set up can cause serious problems for these machines while disturbing the file system and memory resources. Viruses can easy dodge/bypass the security systems.

A number of anti virus programs are developed and made available to common user after the emergence of virus infected ARPANET in the year 1987.

These anti virus programs checks the system periodically for the commonly known virus definitions and removes/repair the infected files.

Sometimes, viruses and worms are considered separately. As a worm is a particular kind of virus capable to make copies of itself and use the system memory, but it cannot be attributed with other programs.