UNDERGROUND

systems existed, it was a lot harder to warn their managers about the worm. Or tell them how to protect themselves. Or give them a worm-killing program once it was developed. Or help them seal up breached accounts which the worm was feeding back to its creator.

It was such a mess. At times, McMahon sat back and con- sidered who might have created this worm. The thing almost looked as though it had been released before it was finished. Its author or authors seemed to have a good collection of interesting ideas about how to solve problems, but they were never properly completed. The worm included a routine for modifying its attack strategy, but the thing was never fully developed. The worm's code didn't have enough error handling in it to ensure the crea- ture's survival for long periods of time. And the worm didn't send the addresses of the accounts it had successfully breached back to the mailbox along with the password and account name. That was really weird. What use was a password and account name without knowing what computer system to use it on?

On the other hand, maybe the creator had done this delib- erately. Maybe he had wanted to show the world just how many computers the worm could successfully penetrate. The worm's mail-back program would do this. However, including the address of each infected site would have made the admins' jobs easier. They could simply have used the GEMPAK collec- tion as a hitlist of infected sites which needed to be de-wormed. The possible theories were endless.

There were some points of brilliance in the worm, some things that McMahon had never considered, which was impres- sive since he knew a lot about how to break into VMS computers. There was also considerable creativity, but there wasn't any consistency. After the worm incident, various computer security experts would hypothesise that the WANK worm had in fact been written by more than one person. But McMahon main- tained his view that it was the work of a single hacker.

It was as if the creator of the worm started to pursue an idea and then got sidetracked or interrupted. Suddenly he just