Monday, May 7, 2012


Virus! The very whisper evokes an unreasonable fear. Most people are terrified of viruses: visions of months of work going up in smoke, of lost time, and of lost productivity fill their eyes. The cause? A small program capable of attaching itself to others, and reproducing at will.

The word "virus" means poison in Latin, but a computer virus is called so because of its striking similarity to a biological virus. Biologists have been debating for years whether a virus is living or non-living. It seems to be just some nucleic acid wrapped in an envelope of protein. It is incapable of respiration, doesn't need food, cannot grow, but still has the most important property to claim it to the living: it can reproduce itself. A biological virus attaches itself to the surface of a living cell, and injects its life molecules, its DNA into the host cell. This DNA comandeers the machinery of the cell, and gets the cell to do its bidding. The captured cell then begins to produce viral protein, and viral DNA, and to assemble it into baby viruses.

Similarly, a virus is a computer program that cannot exist on its own. It needs to attach itself to another program, and takes over the working of that program. Once it takes over the working, it can begin to produce copies of itself, which can then infect other programs. In the process, it may make your computer sick, just as a biological virus makes you sick. Computer viruses are transmitted to others just as ordinary viruses. Promiscuous behaviour, like sharing floppy disks is an important cause.

© 1994-2012, Sualeh Fatehi. All rights reserved.
This article was written in 1994, and never published.