UNDERGROUND

the copied file. Choosing overseas sites would make it even harder for the admin to reach the admins of those machines and warn them in time. Then, once Zardoz was safely tucked away in a few back-up sites, Phoenix could download it over the Internet from one of those with less risk of being booted off the machine halfway through the process.

Sitting at his home in Kelvin Grove, Thornbury, just two suburbs north of the CSIRO machine, Ian Mathieson watched the hacker break into his computer again. Awoken by a phone call at 2.30 a.m. telling him there was a suspected hacker in his computer, Mathieson immediately logged in to his work system, DITMELA, via his home computer and modem. The call, from David Hornsby of the Melbourne University Computer Science Department, was no false alarm.

After watching the unknown hacker, who had logged in through a Melbourne University machine terminal server, for about twenty minutes, Mathieson booted the hacker off his system. Afterwards he noticed that the DITMELA computer was still trying to execute a command issued by the hacker. He looked a little closer, and discovered DITMELA was trying to deliver mail to two Melbourne University accounts.

The mail, however, hadn't been completely delivered. It was still sitting in the mail spool, a temporary holding pen for undelivered mail. Curious as to what the hacker would want so much from his system, Mathieson moved the file into a subdirectory to look at it. He was horrified to find the entire Zardoz archive, and he knew exactly what it meant. These were no ordinary hackers - they were precision fliers. Fortunately, Mathieson consoled himself, he had stopped the mail before it had been sent out and secured it.

Unfortunately, however, Mathieson had missed Electron's original file - the bundle of Zardoz copies. When Electron had mailed the file, he had copied it, leaving the original intact. They were still sitting on DITMELA under the unassuming name .t. Mailing a file didn't delete it - the computer only sent a copy of the original. Mathieson was an intelligent man,