Computer viruses vs biological viruses
MRC News
Computer viruses and 'real' biological viruses are bugs that make our lives
difficult. According to molecular microbiologist Dr Trudy Wassenaar, they share
more than a few common characteristics - and these similarities can help us to
understand and control both better. Find out why computer viruses can be likened
to STDs.
Dr Wassenaar, currently an MRC-funded Distinguished Visiting Scientist based
with Prof. Al Lastovica (Department of Medical Microbiology, University of Cape
Town), says that computer programmers and biomedical clinicians have a lot more
in common than they might think. Like viruses, for instance.
"Our knowledge of biological viruses can help identify the routes that
virus programmers have taken, and will take, in due course. But less obviously,
the Internet is a real-time evolutionary model of infectious diseases for
clinicians to study," she says.
Striking similarities
Both biological viruses (living organisms made up of DNA or RNA inside a
protein coating) and their cyberspace counterparts (computer programs written by
mean-minded computer boffins) parasitise on their host and can only replicate
when inside that host.
"Biological viruses enter their host through an opening after passively
being breathed in, swallowed or via direct contact. Virtual viruses also enter
their 'host' passively when you insert an infected disk or open an infected
e-mail attachment. Similarly to a biological virus which has to have the correct
host and tissue specificity to gain a foothold - a horse virus wouldn't make a
human being sick - a computer virus has to be compatible with the system to gain
a foothold."
"The damage these viruses do, is also similar. Biological viruses
replicate at the cost of the host - damage can include pain, suffering and even
death. Computer viruses slow down the computer - files can become inaccessible
and even lost, and sometimes the complete hard disk gets damaged," Dr
Wassenaar explains.
Worms and viruses
The term 'computer virus' can actually mean one of three things: a virus (a
program that implants a version of itself in any program it can modify and then
spreads to files within a computer, or with user interaction like sharing
infected disks, between computers), a worm (a harmful program that spreads
copies between computers in a network, such as the Internet, without user
interaction) or a Trojan horse (a program that makes a computer available to
non-authorised users).
A virus, worm or Trojan horse can (like HIV) be latent, only to become active
after a certain period. This is called a 'logic bomb'. These three classes of
computer malware can also have hundreds of variants or several slightly modified
versions, which parallel microbial diversity.
Spreading across boundaries
Dr Wassenaar draws some interesting parallels when it comes to the
dissemination or spread of viruses. "Because worms spread without any user
interaction, they are like socially transmitted diseases such as influenza, that
have the potential to infect everyone susceptible. In contrast, computer viruses
are like sexually transmitted diseases. Their spread (through sharing infected
diskettes) is like that of STDs, whose spread is related to specific behavioural
practices. 'Logic bombs' are like HIV, because they are only activated at a
later date," she explains.
As with biological viruses, simple hygiene measures can protect you against
computer viruses. "Just as people would wash hands frequently, avoid
exposure to people with colds, or use condoms to protect against infectious
diseases, computer users should mistrust (and thus not open) files received
through unexpected channels or with unknown extensions or subject lines, request
confirmation from the sender before opening attachments, and regularly back up
hard disks to reduce the risk of losing data," Dr Wassenaar says.
Fortunately, we do have anti-virus programs. "But virus protection
programs are only as good as the last virus recognized, providing only partial
protection at best," she warns.
Auto-immune diseases
When your body's immune system runs out of control and starts damaging
itself, this is known as an auto-immune disease. Similarly, computers can also
fall prey to such diseases. "Recently, a 'warning' turned out to be a
not-so-harmless hoax. The hoax warning stated that certain files were infected
by a computer virus. Heeding the warning, unsuspecting computer users removed
the affected utility files from their computers' operating system. Fortunately,
this time it only turned out to be a mild nuisance, because the computers
weren't permanently damaged. But a more malignant hoax could be as devastating
to computers as some auto-immune diseases are to humans," Dr Wassenaar
says.
Biological viruses also 'steal' virulence genes from other viruses and become
more malignant. This also happens in the case of computer 'malware'. "Just
a week after the September attack against the United States, a highly dangerous
worm called Nimda was released. This combined the most powerful strategies of
two other worm programs, and spread more rapidly than any other previous worm.
Clicking on the subject line of an infected e-mail (to delete it, for instance)
itself activated the worm. But because this worm was so fast moving, so
potentially dangerous, people saw it right away and responded, so slowing its
spread," she explains.
This is similar to the biological world, where with outbreaks of haemorrhagic
fevers such as Ebola, the immense threat of high contagion and lethality prompts
effective measures to rapidly recognise outbreaks and prevent pandemics.
What can we learn?
Dr Wassenaar thinks we can learn from biology. Nature has evolved immunity
that protects plants and animals against a broad range of pathogens. "In
any human being's gut there are native microflora that render partial protection
against infections. Could we perhaps design 'benign' computer viruses, that
could spread through the Internet in an uncontrolled manner, automatically block
entries for malign viruses, update our antiviral programs or inactivate existing
viruses? Microbiologists can help programmers to combat viruses - computer
immunity may be expensive, but eventually we'll have to accept the risks and
costs involved," she says.
But, conversely, the study of computer malware may help to control infectious
disease emergence. "The Internet is a good model to study the development
of infections and how they spread through our increasingly small world. The
speed of virtual pathogen evolution makes it possible to follow the process of
mutation and selection real-time," Dr Wassenaar argues.
More information
Dr Wassenaar has a Ph.D. in Natural Sciences and is a trained molecular (micro)biologist.
Her major field of work is bacteriology (enteric diseases) and since 1999 she
has worked as a research consultant for her own company, Molecular Microbiology
and Genomics Consultants. In addition to consulting on fundamental and applied
research for Academia (including UCT) and governmental agencies, Dr Wassenaar is
also the Curator of the Virtual Museum
of Bacteria. "It was the combination of a genuine interest in
infectious diseases, an overload of virus-generated e-mails, and a creative
mind, that resulted in the virus comparison," she says. An article was
published in Emerging Infectious Diseases (2002; 8: 335-336). More information
on computer viruses can be obtained at http://www.symantec.com,
http://www.mcafee.com, http://www.f-secure.com
and http://www.Vmyths.com.
This article courtesy MRC News
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