alchemyst - 6:31 pm on Oct 26, 2009 (gmt 0)

Do you have an open forum?
Any new members lately with "unusual" email addresses?

I had the same problem on one of my sites and found that someone had gotten through my forum spam filters and posted "bad stuff" deep inside my forum.

Once I found and deleted them and the account, then plugged the holes, bandwidth went back to normal.