So I have a vbulletin forum running on a very good server, as of recently it has been maxing out and reaching over 950 server load. I am paying too much for this server to be getting maxed out. Here is my hosting has said.
It looks like this is the file being exploited, /public_html/vbseo.php . I suggest making sure your vBSEO is updated, *vBSEO Security Bulletin* All Supported Versions: Patch Release. Let us know once you've updated that (if it's not already up-to-date), then we can continue troubleshooting further if the problem persists.
I renamed the vbseo.php to vbbseo.php and the server load instantly dropped back to normal. I would suggest contacting vBulletin directly for support since I don't think you can edit much with that vbseo.php being renamed. Also, I would ask them if they had any tools to verify that your server/site isn't further compromised.
We apologize for the inconvenience but it seems that your server has been exploited through that vbseo.php file. Since it isn't something we provide support for there's not much we can do.
Perhaps someone here has run into a similar problem? Maybe someone found a way to max out / exploit the server via a vbseo script?