Ping.exe is a process that is being run by a rootkit. If you have the same problem I did then the process is devouring your memory up to 100%. I tried about twenty different solutions over a sixteen hour period before I found the solution and removed the rootkit. The solution is a free program called TDSSKiller from Kaspersky. Download it, launch it, scan your system, delete the rootkit, reboot your system via TDSSKiller's prompt, and when your system restarts you're good-to-go. I
You can get this from their site too.
Edit: Unfortunately, the video seems to have been removed from youtube. However, you can still follow my instructions and download from Kaspersky's website, rather than download from mediafire, if you prefer.