UBB.Developers Forums General Discussion Chit Chat Forum Problems

Can anyone help i have run a forum for 5 months now and since i upgraded it to 5.47c i have had a weird problem on sunday someone deleted all my members and closed all my forums and left just me the admin on the members list i thought this maybe my isp as i was to change over to a faster server but it wasnt so i put the forum back to the way it was before working that is and now it has haoppend again but everyone was deleted this time same a before what i want to no is how can this happen i have installed some hacks but it worked ok for weeks after i installed them is it possible for some idiot to gain access to my cp and delete everyone i`m not that great at ubb do i have some file in my cgibin chmod to something is shouldnt be letting people hack me please help as it`s a pain in the ass to restore it all the time ....

Sorry if i shouldnt have posted here ...