Firfox says -->

Reported Attack Site!

This web site at miamix.extra.hu has been reported as an attack site and has been blocked based on your security preferences.

Attack sites try to install programs that steal private information, use your computer to attack others, or damage your system.

Some attack sites intentionally distribute harmful software, but many are compromised without the knowledge or permission of their owners.

;-(

start by taking your site offline.

Secure your server. If you cannot do it ask your host

Once your server is secure make a fresh install of elgg using the same database.  

thanks for your tips, let me try