Well that's mostly because it was pirated version of vBulletin lol. The hosting forced me to upgrade PHP past what was supported and I couldn't update vB anymore.
They want over $200 to upgrade now. They used to charge $30 for the updates after you bought the license, which I did back then but now it would just be a waste.
We already got hella spam bots registering though. I had to keep changing user permissions. I was getting emails and all kinds of shit within hours of bringing the site back up.
The bots are easy to fix since they just submit a basic form to the server. Just rename the controls from "username" and "password" to like "asdasd" and "j4hjk234532" and then the server will just reject all of their bogus submissions.