hackers hacked my website please help my

[ilsat]

hi
hackers hached my website and can change all post in my website
please help my that why i can avoid this attact ?
this is my web address : www.ilsat.ir

[dtv100]

make sure register user group is set to cant edit others post or threads.

[Marco van Herwaarden]

Please read the following thread on how to improve security for your board:
http://www.vbulletin.com/forum/showthread.php?t=194701