hacked forum

Recently I can't log in my forum. I doubt that someone hacked it. Whenever I try to log in, it immediately redirect to other page. If I could access admin page, I was able to restore my forum by using backup. Now there is no chance to do this. Could you help me to solve the problem.I'll give you my account info as soon as you reply. Thanks !
Here is my forum: 1giay.4forum.biz
Log in page: http://1giay.4forum.biz/login

Hello,

Can you please provide your creation email address by PM ?

Edit : It has nothing to do with a hack, it was something in your templates.

I've changed the version of your forum, it's on PhpBB3 so that templates are disabled and you have access to your forum.
I don't know which template is concerned, so please tell me if you want me to delete all the modified templates.
You can also provide your creation email address so that I'll be able to send you a new password.

Thanks