Computer viruses are programs that jump from computer to computer, just as real viruses jump from person to person.
Computer viruses typically enter a computer system through E-mail and file attachments via the Internet and online services, or through illegal or borrowed copies of software.
Viruses have been around computers for a long time. Originally viruses lived in program files that people download using a file transfer program or their web browsers.
Computer viruses not only overwrite the recipient’s computer files but also create a back door so that the virus originator can get onto the recipient’s computer at any time at a later door.
While some viruses use inly infected messages to propagate, many of them can also use other infection mechanisms in order to increase their spreading rate.
Copies of shareware software downloaded from the internet can be another source of viruses.
For example, a Trojan horse program whose purpose is to infect other programs could be planted on a software bulletin board that permits users to upload and download programs.
When user downloads the program and then executes it, the program proceeds to infect other programs in the user’s system.
Thus, as a good practice, avoid using software from questionable sources without checking for viruses.
Also need to use regularly antivirus programs that can help diagnose and remove computer viruses from infected files on hard disk.
How do the computer viruses spread?
