1. In the year 2000, there was a wide outbreak of the QAZ virus/trojan. The trojan leaves allows remote control TCP port 7597. Rumor has it that a Microsoft engineer disklike the performance cost of running anti-virus and disabled it. The engineer then got infected with QAZ. Somebody trolling on the Internet found the open port, remotely controlled the machine, and used it to log back into Microsoft and was able to steal some source code. From Hacking-Lexicon