i have a fairly new forum which seems to be a target for the always tenacious spammer. I have registration set up to include a security question as well as email verification. Is there anything else i can do? I have other forums...in a less popular niche...which receive almost no spam.
NoSpam is your best bet. It blocks 100 percent of automated spam bots. BTW, I use only one question, and am a happy customer of the mod. Its a must have to any VB board.
You need to use a combination of reCaptcha and a Q&A. There are other modifications that implement other little tricks just in case the first two methods don't work.
With the recent rise in spam attacks on vBulletin, I did an article demonstrating several ways to secure your forum Have a read: Reducing Spam
Starting with VB 3.7 - I think it was that version - you now have some human verification options to help you. These are in the left hand column, inside the vbulletin options drop down menu. These built in tools include: Image verification ReCaptcha Question and Answer After you set one of them up, go into vbulletin option - new user registration - and set the one you want as default. Personally, I use ReCaptcha.
Also it would be best not to allow the users to post links (in signature as well as in their forum replies) till the post count is... say 5+ or 10+