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Information Security News
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Decades after creation, viruses defy cure
From: InfoSec News <isn () c4i org>
Date: Wed, 26 Nov 2003 01:44:13 -0600 (CST)
Forwarded from: William Knowles <wk () c4i org>
http://news.com.com/2009-7349_3-5111410.html
By Robert Lemos
Staff Writer, CNET News.com
November 25, 2003
Of all the accomplishments in the annals of technology, Fred Cohen's
contribution is undeniably unique: He introduced the term "virus" to
the lexicon of computers.
The University of New Haven professor used the phrase in a 1984
research paper, in which he described threats self-propagating
programs pose and explored potential defenses against them. When he
asked for funding from the National Science Foundation three years
later to further explore countermeasures, the agency rebuffed him.
"They turned it down," said Cohen, who is also principal analyst for
research firm Burton Group. "They said it wasn't of current interest."
Two decades later, countless companies and individuals are still
paying for that mistake. The technology industry has yet to find a
blanket solution to the ever-growing list of viruses and worms that
constitute the greatest risk to computers on the Internet. Every year,
companies lose billions of dollars when forced to halt work and deal
with infectious digital diseases, such as Sobig and Slammer.
While much attention has been paid to the malicious online attackers
who exploit technology's vulnerabilities, little has been documented
about the origins of the virus. Its early iterations were not created
by malcontent teenagers or antisocial geeks but by campus researchers,
system administrators and a handful of old-school hackers who thought
that the ability to reproduce their programs automatically was a neat
trick.
The result is a tale of technical genius, academic naivete,
bureaucratic arrogance and humans' penchant for tearing down
institutions simply for the sake of doing so.
Sarah Gordon, senior research fellow at Symantec Security Response,
caught her first computer virus more than a decade ago. She became so
fascinated with the phenomenon that she spent several years studying
the underground world of virus writers.
"The design of the Internet facilitates the distribution of
information--all sorts of information; it's a double-edged sword,"
Gordon said in a recent e-mail interview. "Even if (viruses) are not
designed to be intentionally malicious or dangerous, if they get
outside of a controlled environment, there can be unexpected results."
That was precisely what happened with the fathers of the computer
virus: The exponential doubling of viral code can greatly magnify
minor errors and become the difference between a harmless prank and a
devastating attack. Unlike the simple technologies behind isolated
attacks on the Internet, the ability to propagate adds a level of
complexity that often stymies the virus writers themselves. Although
many programs quickly fizzle out, others have far outgrown the
intentions of their authors.
Cohen had an inkling of much of the future when he first thought up
the idea in November 1983 as a University of Southern California
graduate student. During a weekly seminar on computer security, he
conceived of a program that could infect other systems with copies of
itself.
"All at once, a light bulb came on, and I said, 'Aha!'" Cohen
recalled. "Within a few seconds, I knew how to write the program and
that it would work."
His adviser at the time, Len Adleman--well known as a creator of
public-key encryption and the "A" in a popular form of the security
technology known as RSA (Rivest, Shamir & Adleman)--suggested that the
programs were the digital analogy of viruses. The name stuck.
The birth of a concept
In a paper published the next year, he defined a virus as "a program
that can 'infect' other programs by modifying them to include a
possibly evolved copy of itself." Cohen proved that such a virus could
spread through any system that allows information to be shared,
interpreted in a general manner and given away, despite the presence
of security technologies.
To demonstrate its potential dangers, Cohen created a test program to
see how quickly the virus could spread and undermine the security of a
mainframe computer system. He implanted the program in a command that
presents Unix file structures graphically, then conducted five attack
runs.
The virus managed to "gain system rights"--essentially seizing control
of the computer--within an average of half an hour. The shortest run
took five minutes.
"It could spread with all the security technologies out there at the
time," Cohen said. "The concept showed that the least trusted user is
the weakest link, and the program can quickly spread up to the most
trusted user."
Cohen's work provided a concrete definition of a virus and showed how
other programs, such as worms, are a subset of that definition. But a
few viruslike programs existed before his research, and many of its
theoretical underpinnings were established by John von Neumann, one of
the founding fathers of computer science.
Born in Hungary in 1903, von Neumann was responsible for seminal work
in many branches of computer science, mathematics and physics,
including logical analysis of a strategy called game theory and the
newly born branch of quantum physics. Between 1948 and 1956, he
extended much of the work of one of his peers, famed computer
scientist Alan Turing.
Turing had come up with an idea for a universal computing system, a
logical construct that could solve a wide variety of problems by using
a processor and a tape to store programs and data. Computers still use
the basic division of labor Turing identified: processors and storage.
Von Neumann expanded Turing's concept to the creation of a universal
constructor, a system that could replicate itself. This
self-reproducing automaton, as he called it, used tens of thousands of
elements--each of which could be in any of 29 states--to create
another automaton on an imaginary grid. The system was so complex that
it took more than 40 years for even a limited version of it to be
implemented in hardware.
Survival of the fittest program
Von Neumann's work later served as the foundation for a new branch of
computer science known as cellular automata theory, and it inspired
other researchers to create simpler computer "creatures" and the field
of artificial life. His pioneering research also spurred three Bell
Labs researchers to put his ideas into action in the early 1960s.
In August 1961, researcher Victor Vyssotsky invented a game, dubbed
"Darwin," in which small programs competed with one another to
dominate a digital landscape. His colleague Douglas McIlroy programmed
much of the game, including the code that would run the simulation.
The third researcher, Robert Morris Sr., created a lethal digital
creature that evolved and passed along its successful attack to its
progeny.
"It was clear that by tinkering the rules to introduce a bit of
uncertainty into the game, we could have revived it after Morris'
devastating entry, but we had other things to do," said McIlroy, now
an adjunct professor in the computer science department at Dartmouth
College. The game ran on an IBM 7090 system and was largely forgotten.
However, the researchers and their progeny were to have a profound
impact on computers and the Internet.
Morris went to work for the National Security Agency. In November
1988, his son, Robert Jr., created the first worm to spread widely
across the Internet. While "Darwin" didn't survive the evolution of
its IBM 7090 computer system, the researchers' recreational activities
led to the invention of a more popular game called "Core War," where
players write battle programs in a language called Redcode and duke it
out in a virtual-memory arena dubbed the Memory Array Redcode
Simulator, or MARS. Many aficionados still play the game on the
Internet.
But those digital creatures were all contained in artificial
environments. It took a different game to help introduce viruses to
computers and spread infections worldwide.
That game was "Animal," a program akin to "20 Questions," which became
highly popular among mainframe computer operators in the 1970s. The
game would ask a person to think of an animal and then ask questions
for clues as to the type of creature it was. If the program guessed
wrong, it would ask the player to provide a question and an answer
that would differentiate the new animal.
John Walker, a UNIVAC (Universal Automatic Calculator) systems
programmer for a large multinational firm, created his own version of
the game in 1974, improving it so that erroneous information one
player enters could eventually be corrected by another. The game was
an immediate hit.
"I started getting calls from people at other UNIVAC installations
asking for tapes of the game," he said.
From games to viruses
In the pre-Internet days, Walker found himself telling people to mail
him a tape, onto which he would copy the program and return it. He
quickly tired of the laborious process: "It was really annoying and
got me thinking on how best to distribute the game. That's when I
thought about making it self-reproducing."
In January 1975, Walker created another program, "Pervade," which
would hitch a ride with a new version of "Animal." Any time someone
played the "Animal" game, Pervade would also start running to check
directories, duplicate itself in any directory that didn't already
have a copy and overwrite any older versions.
Walker recalls reflecting on the implications of the program for a
couple of months to ensure that he hadn't made any damaging errors.
Then he released it.
Within a week, UNIVAC administrators at another corporate office
started reporting that "Animal" had suddenly appeared on their system.
Weeks later, other companies discovered the program on their systems
as well.
"A few months later, a lot of people started talking about it, and
that meant more people were asking for it," Walker said. "It
propagated as much by word of mouth as by copying itself to new
directories."
The Pervade program stopped working when UNIVAC released a new version
of the operating system that changed its directory structure. But
Walker insists that a modified copy of his program could have easily
overcome its new security features.
"UNIVAC was putting forth all these security methods, and here was an
example of a threat that all the defenses couldn't do anything about,"
he said in comments Cohen would echo a decade later. Walker went on to
found Autodesk in the early 1980s, and he remains the largest
individual stockholder in the company.
In a testament to the unpredictable nature of viruses, even Walker
guessed wrong about how long his self-replicating creation would last.
He recently talked to an administrator of a Unisys 2200 system, a
descendent of the UNIVAC computers, who reported that the program
still runs on his machine.
"It's still looking for file system tables that are 30 years out of
date," Walker said.
The host in the machine
Viruses proliferated exponentially with the popularity of desktop
computers. Not only did individual computers enlarge the pool of hosts
a virus could infect, but they also yielded a new techno-savvy
generation armed with the knowledge to create such programs.
Rich Skrenta fit the bill to a tee: A Pittsburgh-area ninth-grader in
1982, he knew a lot about the Apple II and loved to use software to
play practical jokes on his classmates. The then-teenager supplied his
friends with Apple II programs to which he had added some custom
"features," such as the machine's ability to shut down automatically
after being used just a few times or to display a taunting message.
"After I had done this a number of times, no one would take games from
me anymore," said Skrenta, now the president of his own,
soon-to-be-launched search start-up, Topix.net. "And so, I was
puzzling on how to get my tricks onto their disks."
That's when he got the idea to write a self-propagating program that
would infect Apple II disks. Skrenta's idea for "cloner" programs--he
didn't employ the term virus--would infect a popular command on the
system disks used by the Apple II. The program he created, called Elk
Cloner, counted how often a disk had been used and, on every fifth
run, made the computer shut down or perform some other "trick." Every
50th time the computer started up, Elk Cloner would display a little
poem.
Four years later, two Pakistani brothers, Amjad and Basit Farooq Alvi,
created the first computer virus to infect IBM PCs. Known as the Brain
virus, the brothers used the program as a piece of true viral
marketing: Each copy caused a message to flash on the screen,
advertising the brothers' company, Brain Computer Services of Lahore,
Pakistan.
"Beware of this VIRUS...Contact us for vaccination," stated the
message, which can be found on their Internet site today.
That was only the beginning. Although viruses and worms took more than
a decade to emerge in significant numbers, they soared in subsequent
years. By the end of 1990, about 200 viruses had been identified.
Today, that number has jumped to more than 70,000. Although less than
1 percent of those viruses have compromised computers on the Internet,
more than 80 percent of companies suffered a digital infection,
according to the Computer Security Institute.
Symantec's Gordon said most virus creators--not unlike their
predecessors--still don't understand the ability of the programs to
spread throughout the Internet. "They tend to be curious--often
articulate individuals with a variety of relationship and interaction
styles," she said.
Cohen, however, said the scientific heavy lifting for today's Internet
viruses was done in the 1980s. Everything else, he said, is just
mechanics.
"Everything that we know now was known then," he said. "Everything we
see now is just an engineering solution based on old science."
*==============================================================*
"Communications without intelligence is noise; Intelligence
without communications is irrelevant." Gen Alfred. M. Gray, USMC
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