I have a small vBulletin discussion forum Version 3.8.1. There is CAPTCHA based image-text during registration but it seems like spam bots have now (or since some time) found a way to 'read' these images.
There is not much traffic, members or spam even but we want a good solution for controlling the spam. Possibly, something like:
1. having the image hidden at first and only when the cursor is hovered at this image one should be able to the image. I have seen such a function at one forum but can't recall where.
2. to ask more intelligent questions based on 5-10 images. For instance images role and the registering user (or bot) is asked to see the images and click on the image which is Earth. If then the earth is clicked registration is complete. Otherwise not and the IP address of the bot is blocked.
We would probably like to continue using vBulletin but you may be allowed to upgrade the version if that is really necessary. Of course no data of our forum should be lost during this process.
I think its a small task and hence expect an affordable bid and time estimate.
Also reading these articles/posts may help you get more ideas on how to do this:
1. [url removed, login to view]
2. [url removed, login to view]