Spambots

[bojomojo]

Is there anything to install to prevent spambots or help in that?

[Andy Huang]

Enable spam management feature with an Akismet key.
Admin CP > vBulletin Options > Spam Management

You can get your Akismet key by going to http://akismet.com

Beyond that, you should also enable human verification at registration process (if you've not already done so).

These two features combined kills most spam I get... For those that tends to slip by, there are some good keyword based anti spam addons on vbulletin.org which you can use, too.

[bojomojo]

is it the same used for wordpress? the same key i mean?

[cheat-master30]

I think the same key would work as for your blog. My advice for stopping spam bots then is also to add many known spammer type domains and emails to your ban lists, use question and answer verification with custom questions and to maybe require email validation.