i doubt anyone 'hacked' your server, its not simple in the slightest. I suggest you change the people you trust with access to your console and 'ftp server' as for the help, do it yourself its better that way you need not rely on anyone else to screw things up.
If you need help in how to format and use groupmanagers group files, refer to this: read-here-for-groupmanager-help-t272249.html

Note: the above link is still being changed