Butler was sentenced Monday to 18 months in prison for launching an
Internet worm that spread through hundreds of military and defense
contractor computers over a few days in 1998.
In handing down the sentence, federal judge James Ware rejected defense
attorney Jennifer Granick's argument that the Air Force, and other victims
of the worm, improperly calculated their financial losses from the hack.
The judge also declined to give Butler credit for his brief stint as an
undercover FBI informant, during which he infiltrated a gang of hackers
that had penetrated 3Com's corporate phone network.
But the judge refused prosecutor Ross Nadel's request that Butler be
immediately taken into custody in the courtroom, and allowed the hacker to
remain free on bail until June 25th, when he's scheduled to report to
prison. With credit for good behavior, Butler will be eligible for
assignment to a community halfway house as early as April of next year,
and will be released in mid-October 2002. He'll then serve three years of
supervised release during which, under a special order, Butler will be
barred from accessing the Internet without permission of his probation
officer. Ware also ordered Butler to pay $60,000 in restitution.
A consultant who specializes in performing penetration tests on corporate
networks, the 28-year-old remained well regarded in computer security
circles even after his March, 2000 indictment. Butler is known for his
expertise in intrusion detection: the science of automatically analyzing
Internet traffic for "signatures" indicative of an attack, and he created
arachnids, a popular open source catalog of attack signatures that forms
part of an overall public resource at
Butler, known as "Max Vision" to friends and associates, crossed the line
in June of 1998, at a time when much of the Internet was still vulnerable
to a hole that had been discovered months earlier in a ubiquitous piece of
software called the BIND "named" domain server. The hacker group ADM
published a computer program capable of spreading through vulnerable
systems automatically. Butler launched a special strain of the worm that
penetrated systems, but also automatically closed the BIND hole as it
spread, forestalling attacks from other hackers.
Tall and soft-spoken, wearing a blazer and rumpled cargo pants, the hacker
apologetically told Judge Ware that he got caught up in the need to close
a serious security hole.
"I got swept up," said Butler. "It's hard to explain the feelings of
someone who's gotten caught up in the computer security field... I felt at
the time that I was in a race. That if I went in and closed the holes
quickly, I could do it before people with more malicious intentions could
Butler did not address why he left malevolent features from the ADM worm
in his own program, including one that created a secret back door on every
system it penetrated.
"What I did was reprehensible," Butler told the court. "I've hurt my
reputation in the computer security field. I've hurt my family and
Judge Ware emphasized the need to deter other hackers. "There's a need for those who would follow your footsteps to know that this can result in incarceration," said Ware. By Kevin Poulsen