its more likely to be a SQL injection there was a new one around the net last week. how ever i know Vb seem fast to fix on known exploits and the only mod that i can think of that has a known exploit at the moment is vbplaza with the donate button. unless you left your install path could be social engineering send me a pm i have a few sites that may help you if you want to know about how and why it happens.
I am quite late to ask you this question. I am seeing your site / forums is working fine now. First of all congratulations. Can you please tell me how you have succeeded in getting your site back. Thanks in advance.
Hi Maksa, Next time this happens (hopefully not!), search your database for the hackername which shows on your index. Most of the times they use SQL injection to change your forumhome, forumdisplay templates and that causes the issue which you were talking about. A simple fix would have been finding them in your database and replacing their code from a backup of your code, or re-installing the skins. Unfortunately I believe I am a bit late in telling you this, but it has happened to me recently and I am trying to figure out what caused it. I have very less hacks installed on my system at present and this is pretty annoying. If you would like we can correspond and try to figure out what might have caused this.