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The
Canary in the Network
By Richard Thieme
Like last weeks
weather, the Melissa virus is old news, but its lessons have
once again probably been forgotten already.
Melissa is a
canary on its back, its little legs twitching in the air, but we
tunnel on through the mountain as if we are safe and the square
foot of dirt illuminated by our light is all we need to see.
Because of a
rapid response to the virus, little serious damage was done by Melissa,
a Word macro virus propagated by email on networks using Microsoft
Outlook. Still, over a single weekend, Melissa had reached more
than 100,000 computers and some sites had to take their email systems
off-line. Had Melissa been designed to do serious damage, things
would have been much worse. Still, thousands of hours of down time
and interrupted communications reveal the real vulnerability of
our networks.
Melissa may
be a sign of things to come. It all depends on the choices we make.
The world of
computer security constitutes an infrastructure on which global
commerce and communication rest. Its a multi-level world of
thrust and parry, offense and defense designed and refined at every
strategic level, from code to top-level domains where the message
is the medium.
At the code
level, Melissa is one of many viruses that take advantage of weaknesses
in Microsoft software. When Microsoft decided to dispense with a
security kernal, they ensured that every user of their software
has the equivalent of "root" status, reserved in UNIX-based
systems for a privileged few. For all practical purposes, there
are no viruses in UNIX, MVS, VMS, MPE and other operating systems
that run on workstations, minicomputers and mainframe computers,
observes Mich Kabay, Director of Education, ICSA, in a letter to
the Atlantic Monthly. Only Microsoft built systems that could be
so easily compromised.
Many virus writers
view Microsoft as an evil plague and resent what they believe to
be false claims, that Microsoft provides operating systems with
robust security. They write code designed to explode those claims.
It used to require
a master programmer to write a good virus. Today, script kiddies
can cobble together code from the Internet and make a lethal bomb.
That means confidential
communication can be compromised, even by a virus as simple as Melissa.
More destructive code can stop commerce in its tracks. Network users
dont usually care about technical details, they just want
the telephones to work. But are they willing to pay a higher price
in terms of inconvenience and heightened awareness as the threat
increases?
To travel by
air, we are willing to answer a few questions and show IDs at the
ticket counter, then move slowly through metal detectors. Laptops
are booted up or sniffed for chemicals. A short time ago, such restrictions
would have seemed excessive, but awareness of a real threat made
them tolerable. Still, those measures are minimal compared to airport
security in Israel, for example, where I recently arrived for a
flight four hours early and was interrogated twice at some length.
When we realize
whats at stake, we will do what we must to maintain safety.
Unfortunately, there must often be serious losses before that moment
arrives.
A free market
economy relies on a handshake to get deals done. Despite all our
laws, the basis of an efficient marketplace is trust. Trusted human
networks work in relative freedom, as information networks do. Both
were originally designed to facilitate the flow of information,
not security.
The amount of
downtime caused by Melissa, a relatively benign virus, is a twitching
canary in the coal mine of the Net. Unless we become conscious of
the price we would pay if a lethal virus was unleashed, we will
stay asleep at the switch as innocuous packets enter our networks
by stealth.
Melissa, or
"The Canary in the Network," was originally published
in Information Security magazine, a publication of ICSA, Inc.
1999
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