Possible Duplicate:
How do I get rid of malicious spyware, malware, viruses or rootkits from my PC?
I recently identified some suspicious CPU activity on my Windows 7 x64. While idle in task manager top processes consume about 5-7% of CPU, but in Performance tab I can see about 25-30% consumption. With my i5 Intel (2 cores / 4 threads) this suggest, that there is running single thread app consuming whole core, but it is not listed in Task Manager.
I have scanned computer with Windows Defender and Avast, but they found nothing.
Any ideas how to track, what process is consuming so much CPU?