Hi I recently connected my computer to a dorm network and I had 3 moth old definitions on my symantec antivirus. I got the trojan called perfcoo or perfc000.dat I do not know how I got it as I was not using my computer when the security alerts began appearing. The symptoms are that if I have symantec active protection on I get about 3 alerts per second about perfc000.dat until my computer locks up after about 10-15 minutes. I have followed the symmantec instructions to remove this trojan but it did not work, the trojan just appeared again immediatly after removal. Also the registry key m