HEARD the one about the little old lady who was terrified to go into a
computer shop in case she caught a dangerous virus?
We laugh because we know that computer viruses are just inanimate bits of
software. They can鈥檛 leap out of the silicon boxes that house them to harm us,
can they?
Well, don鈥檛 be so sure. Junk e-mails might. Don鈥檛 worry about the wonder
lubricants and free satellite TV. The one to watch is the Get Rich Quick message
that tries to sell you a bulk e-mailer. This consists of a list of addresses
(usually very long) and a program for copying messages to them all. In classic
pyramid-sales fashion, the e-mail urges you to buy the package and earn more by
selling it.
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Like biological viruses, these messages need a host鈥攐r a cycle of
hosts鈥攊n which to reproduce. In this case the hosts are us and our silicon
boxes. And these viruses can cause a lot of disruptive and unpleasant side
effects.
A biological virus holds its information in RNA or DNA. In most computer
viruses, data is held in the program code for a Windows PC. In both, the code is
protected by a surface wrapping, which has to change quite quickly from one
generation to the next if the virus is to survive.
That鈥檚 because the hosts can develop an immune response or filtering system
that looks out for familiar versions of the virus and blocks it. The virus
either moves on or becomes extinct. In a biological virus, the wrapping and
hooks are clever proteins that bind to elements of a host cell鈥檚 surface. In the
electronic virus, the hooks are attention-grabbing enticements such as 鈥淢ake
Money Fast!!鈥�
But people aren鈥檛 stupid, any more than immune systems are. Recipients of
electronic spam soon get suspicious, and start deleting messages that promise
鈥淨uick Money!鈥� or 鈥淓arn Millions!鈥� without even reading them. So virus writers
invent variations, and some of these succeed beyond their wildest dreams. Take
鈥淭hanks for your message鈥�. Like the infamous 鈥淚LOVEYOU鈥�, it tricks you into
thinking it really is from a friend. And the enticements can become even more
subtle: 鈥淚 know you鈥檙e too clever to fall for pyramid selling but . . .鈥�
The bulk e-mailer is an information virus that uses the human mind as a host
for one part of its life cycle and the computer for the other. The computer does
the rapid replicating, while the human provides the resources and adds variation
to stir new interest each time. This is a nasty meme, or, to borrow from Richard
Dawkins, it becomes a 鈥渧irus of the mind鈥�.
It could get scarier. Advertisers and finance houses already use genetic
algorithms to evolve tools that spot trends, lure purchasers and detect bad
credit risks. So that old lady was right after all. You can catch a virus from
your computer, and your computer can catch it from you.