But that's not all. You should also inform the admins at the site from which the attack was launched. We admins have to stick together. It is only polite to inform them what happened. It may also be that they are unaware of the compromise.
Any information can be useful.
But it bounced. It seems their domain was down. So then I did a whois to find out who to send it to. I used the addressed I found below. Please, if you have any comments regarding this, or any other article, add your comments.