...Of course Tsutomu didn't have to explain the technical details to
this crowd. The system's vulnerability had been known for a long time--
two respected security experts, Robert Morris and Steve Bellovin, had
published papers about it years earlier. But it was such an elaborate
method of attack that it had rarely been used. In computer security
lingo, it was "nontrivial." That meant it required a lot of time, a
lot of patience, and a lot of guts.
Not only that, but much of the attack appeared to have been automated--
that is, someone had written a computer program which carried out the
attack. That made the attack all the more alarming, because that meant
it could be done by anyone with enough savvy to run the script-- which
meant, basically, that someone with slightly above average technical
knowledge (by hacker standards, that is) like Kevin might indeed be
able to pull it off.
See Goodell.