This version of UnrealIRCd contains a backdoor. This backdoor allows a person to execute ANY command with the privileges of the user running the ircd. The backdoor can be executed regardless of any user restrictions. The file Unreal18.104.22.168.tar.gz file has been replaced with a backdoor (trojan) around November 2009.
Download the fixed version from http://www.unrealircd.com/.