Spam/ Hackers problem

Hi Everyone!

I'm running Release - 1.6.1, Version - 2009072201 on a site at

I've been experiencing a lot of problems with spurious members (usually based in Chine) that register and then flood the blog area with spam. I keep on deleting the accounts but the problem is getting heavy. I also notice that one of these had hijacked the "Blogs" link and a Viagra ad. came up when it was pressed.

I think I need to be able to validate accounts manually as the auto e-mail verification set-up is not secure enough OR is there a way of filtering this crap? I notice most of the e-mail addresses given are jibberish - surely there's a mod somewhere that could distinguish between rubbish and genuine account registrations.

Any suggestions anyone?

Many Thanks,