Hackers rarely attack using their own equipment directly anymore. The culprit launching the DOS attack is likely an unwitting victim themselves. I'd guess it's probably one of the countless Windows PC's who've not kept their PC's properly patched / protected, so-called "Zombies". Here's the part where I insert a standard warning here about EVER running a Windows PC without some form of firewall, even for a few seconds. I know this is tough if you're building a home PC from scratch, without a hardware based firewall, to protect you while you're feverishly downloading Microsoft's patches. By the way, contary to other posts I've seen, I've never had a problem when I block Poser's access to the Internet.