"Unknown attackers penetrated the server hosting the open source
ProFTPD FTP server project and concealed a back door in the source
code. The back door provides the attackers with complete access to
systems on which the modified version of the server has been
installed. On installation, the modified version informs the group
behind the back door by contacting an IP address in the Saudi
Arabia area. Entering the command 'HELP ACIDBITCHEZ' results in the
modified server displaying a root shell."