First of all, sorry for English.
For a few days users are being created automatically on my forum, obviously is a machine which creates. I have put a Captcha to prevent this, but it is preventing.
What can it be? How I can help?
thanks

Each such a case is individual, users may spam your site by a few reasons. Just recently we have discussed that one of the reasons could be enabled profile's hyperlink. In the same thread you may also follow some of my advices of what else could be done to prevent automated registrations besides Captcha (email verifications, pre-moderation add-on and so on).

Thanks for your answer.
Do not just fix the problem.

Hello again
The problem seems to be that source being injected directly into the database.

Any idea to solve the problem?

thanks

Do you have any proofs, facts, codes?..

There could be no ideas, if there is no exact description of the problem.

I think I've solved it. He added some pages miniBB, they were using to add users. MiniBB was NO problem, but my code.

thank you very much
Juan Carlos