I didn't mean trace the IP back to the host. I should have been more specific.
You'll need to use something like wire shark to record your incoming packets to a log file and then see what kind of packets those IPs are sending to your server (it doesn't matter where they're coming from, you're testing to see if the packet/s they're sending are what's actually crashing your server).
Or you could download the program and manually test out crashing your server with it. If you can successfully crash your server with that software then you would at least have a good idea of what was being used to crash your server. If it doesn't work to crash your server though, then either something else is being used or something else altogether is crashing it.
You may want to be going through your event viewer to see if something else is happening in the background on your system that could be crashing it as well.
Then I'll look deeper, I do have to say I've had the same problems for a little over a year now and Went through three different' versions of Windows.