My forum has been hacked

[~Death Ripper~]

Sombody hacked my forum.. Twice. First time I forund out whose profile he hacked and changed password and everything. They just replaced skin with something like "Now you're screwed, we are Russian hackers" etc., probably somebody copying them. I repat old skin and everything was allright, but now we did a reconstruction (with just hiding forums) and added a widget for changing skins, never mind, it was allright. But then somebody delated it and I used Admin Panel to see IP's of the user who've been hacked last time (sub-admin) and saw this:

Spoiler:

Dinamic IP adress, no? But what can I do?

[Mehtevas]

Please refer to the following link for some more information
https://help.forumotion.com/t75418-my-forum-was-hacked