The modules/mdop.m in the Cypress 1.0k script for BitchX, as downloaded from a distribution site in November 2007, contains an externally introduced backdoor that e-mails sensitive information (hostnames, usernames, and shell history) to a fixed address.
http://www.securityfocus.com/bid/26372
http://www.securityfocus.com/archive/1/483350/100/0/threaded