• 
• 

 1 of 2

Gallery

Viruses

Posted on 19 Aug 2002 at 17:37

With the world facing unprecedented virus threats in both biology and computing, Stewart Mitchell searches for solutions in their similarities

When the first 'in the wild' virus, Elk Cloner, made its debut in 1981, its creator could hardly have foreseen the chain of events he set in motion. From simple disk-spread examples that immobilised boot sectors to the complex mutants of today, viruses have become an intrinsic part of working with computers.
Over 20 years later, his handiwork has spawned an army of script writers and contributed to multimillion pound anti-virus software and security industries.
In all probability, the first virus was called a virus simply because it was unseen and infectious (and carried by humans), but the similarities go further - much further.
According to a study by anti-virus software producer McAfee, at a fundamental level, both computer and biological viruses are made up of strings of basic elements - binary code in the case of computers and nucleotides in biology.
Whereas nucleotides combine to make codons and then genes, binary bits gather in bytes. The genes of a medical virus determine its characteristics and payload, while bytes govern computer virus attributes. Medical viruses are measured by their nucleotide count, and a typical influenza virus holds 13,700 of the beasts, making it a 13.7 Kilobase (Kb) virus. By partial coincidence, both viruses are measured in Kb, with bytes replacing base as terminology moves into the computer. Understanding these building blocks is key to deconstructing all viruses and learning to nullify their threats.
The mechanical similarities don't stop with structure either. A virus, for a start, is not a living thing, but DNA within a protective cloak. As a parasite, it can't reproduce or spread without infecting living cells. Once inside a cell, the virus uses its host to reproduce.
Likewise, a computer virus normally acts in collusion with another file before it can spread itself to other files or computers, but this doesn't stop either from infecting other hosts during suitable contact.
Both also carry a payload, be it the sickness of influenza or AIDS in humans, or the destruction of files and bandwidth use of the computer virus. In both cases, the payload can vary from mildly annoying to devastating.
It goes without saying that the majority of these rules can be applied to many infectious bodies. Bacterial and fungal infections have a lot of the same attributes, as do the various different types of computer viruses. Whether you're talking worms, germs, Code Red or Yellow fever, the similarities ring true.

Changing of the guard
Viruses of both types have seen major changes in the last 20 years, as communications have become exponentially faster, cheaper and more popular. Whereas computer viruses used to take months to cover countries, as they were carted from machine to machine by floppy disks, they can now cross the world in seconds as an email attachment.
Medical experts have also seen a giant step forward in viral migration capabilities, as increasing numbers of holiday-makers and business travellers take to the friendly but poorly ventilated skies.
Before air travel, a virus would have travelled by contact or droplet from host to host, taking years to cross continents. It can now hitch a ride on its host's plane and pass the infection to other passengers as the cabin air circulates. The virus carriers then step off the flight into an entirely new playground and head in any number of directions, all in a matter of hours.
Doctors try to monitor and fight the spread of dangerous viruses, and anti-virus companies are similarly battling to release pattern files as soon as they're seen in the wild. Some, like Trend Micro, are attempting to release identikits for viruses while they work on the patch in a bid to contain the spread. Other major players such as McAfee, MessageLabs and Sophos are also concentrating on rapid turnaround for their customers.