The admin began inspecting the system, perhaps looking for signs of an intruder. Mendax quietly deleted his incriminating directory. Not finding any additional clues, the admin decided to inspect the mysterious directory more closely. But the directory had disappeared. The admin couldn't believe his eyes. Not an hour before there had been a suspicious-looking directory in his system and now it had simply vanished. Directories didn't just dissolve into thin air. This was a computer--a logical system based on 0s and 1s. It didn't make decisions to delete directories. A hacker, the admin thought. A hacker must have been in the NorTel system and deleted the directory. Was he in the system now? The admin began looking at the routes into the system. The admin was connected to the system from his home, but he wasn't using the same dial-up lines as the hacker. The admin was connected through Austpac, Telecom's commercial X.25 data network. Perhaps the hacker was also coming in through the X.25 connection. Mendax watched the admin inspect all the system users coming on over the X.25 network. No sign of a hacker. Then the admin checked the logs to see who else might have logged on over the past half hour or so. Nothing there either. The admin appeared to go idle for a few minutes. He was probably staring at his computer terminal in confusion. Good, thought Mendax. Stumped. Then the admin twigged. If he couldn't see the hacker's presence on-line, maybe he could see what he was doing on-line. What programs was the hacker running? The admin headed straight for the process list, which showed all the programs being run on the computer system. Mendax sent the admin a fake error signal. It appears to the admin as if his korn shell had crashed. The admin re-logged in and headed straight for the process list again. Some people never learn, Mendax thought as he booted the admin off again with another error message: Segmentation violation. The admin came back again. What persistence. Mendax knocked the admin off once more, this time by freezing up his computer screen. This game of cat and mouse went on for some time. As long as the admin was doing what Mendax considered to be normal system administration work, Mendax left him alone. The minute the admin tried to chase him by inspecting the process list or the dial-up lines, he found himself booted off his own system. Suddenly, the system administrator seemed to give up. His terminal went silent. Good, Mendax thought. It's almost 3 a.m. after all. This is my time on the system. Your time is during the day. You sleep now and I'll play. In the morning, I'll sleep and you can work.