In the NorTel network, a mail spool, where email was stored, was often shared between as many as twenty computer systems. This structure offered considerable advantages for Mendax. All he needed to do was break into the mail spool and run a keyword search through its contents. Tell the computer to search for word combinations such as `BNRGATE' and `password', or to look for the name of the system admin for BNRGATE, and likely as not it would deliver tender morsels of information such as new passwords.
Mendax used a password he found through this method to get into BNRGATE and look around. The account he was using only had very restricted privileges, and he couldn't get root on the system. For example, he could not FTP files from outside the NorTel network in the normal way. Among Internet users FTP (file transfer protocol) is both a noun and a verb: to FTP a program is to slurp a copy of it off one computer site into your own. There is nothing illegal about FTP-ing something per se, and millions of people across the Internet do so quite legitimately.
It appeared to Mendax that the NorTel network admins allowed most users to FTP something from the Internet, but prevented them from taking the copied file back to their NorTel computer site. It was stored in a special holding pen in BNRGATE and, like quarantine officers, the system admins would presumably come along regularly and inspect the contents to make sure there were no hidden viruses or Trojans which hackers might use to sneak into the network from the Internet.
However, a small number of accounts on BNRGATE had fewer restrictions.
Mendax broke into one of these accounts and went out to the Internet.
People from the Internet were barred from entering the NorTel network through BNRGATE. However, people inside NorTel could go out to the Internet via telnet.
Hackers had undoubtedly tried to break into NorTel through BNRGATE. Dozens, perhaps hundreds, had unsuccessfully flung themselves against BNRGATE's huge fortifications. To a hacker, the NorTel network was like a medieval castle and the BNRGATE firewall was an impossible battlement. It was a particular delight for Mendax to telnet out from behind this firewall into the Internet. It was as if he was walking out from the castle, past the guards and well-defended turrets, over the drawbridge and the moat, into the town below.
The castle also offered the perfect protection for further hacking activities. Who could chase him? Even if someone managed to follow him through the convoluted routing system he might set up to pass through a half dozen computer systems, the pursuer would never get past the battlements. Mendax could just disappear behind the firewall. He could be any one of 60000 NorTel employees on any one of 11000 computer systems.
Mendax telnetted out to the Internet and explored a few sites, including the main computer system of Encore, a large computer manufacturer. He had seen Encore computers before inside at least one university in Melbourne. In his travels, he met up with Corrupt, the American hacker who told Par he had read Theorem's mail.
Corrupt was intrigued by Mendax's extensive knowledge of different computer systems. When he learned that the Australian hacker was coming from inside the NorTel firewall, he was impressed.
The hackers began talking regularly, often when Mendax was coming from inside NorTel. The black street fighter from inner-city Brooklyn and the white intellectual from a leafy outer Melbourne suburb bridged the gap in the anonymity of cyberspace. Sometime during their conversations Corrupt must have decided that Mendax was a worthy hacker, because he gave Mendax a few stolen passwords to Cray accounts.