Just recovered from a heavy duty spam attack which brought down my site totally.
Most interesting part was this was done without any privileged access to my site altogether. There were about 13k spam ping backs and comments which meant my server drive and db was full. Leaving no breathing space to recover at all.
However, using help from my hosting partners and few searches online I was able to cleanup the mess. Will post a step by step instruction set to recover from such attacks in future.