It seems I have picked up the same malware discussed in the following thread, "Ping.exe and av security 2012 [Solved]". In additional I am seeing suspicious behavior such as my CPU being pegged in my tray icon, but the process is not visible in Task Manager. I downloaded combo fix and followed the direction found in the aforementioned post; however, it complained that avast was still running even after I shutdown all my Shields. It ran all night and never completed.
Please help!