the exact same problem is here too and the problem is not from the server i secure my server very good and i know how to secure my server ( i work as a servers administrator ) .
plus the strategy happens is not from the server side at all it is exploit on the script it self since the hacker load a real BTC on the site and then he bet with ( 1% , 0.5% ) win chance and he success from his first bet , it happens with me with 3 account each was new register account and he just do a single bet with a bet chance just ( 1% , 0.5% ) and win from his first roll and run with all the money from the site .
first time i told he is a very lucky person but then after i see that happens with a different 2 account the same day i was completely sure that this is not a luck .