The "scour" or Rootkit.Win32.TDSS virus has a long history which can be found here: http://en.wikipedia.org/wiki/Scour
Here is the primary symptom: after searching for something in your web browser using google, one of the results that you click on redirects you to scour.com.
If you've executed ClamWin, Malwarebytes, McAfee, Norton, etc. to find and isolate the virus without any luck--this isn't really a surprise, since this virus attaches to existing system drivers.
I only know of one reliable package that will remove this without ill effects--like adding new spyware. This package is called TDSSKiller. I have seen multiple websites that claim to have this software available, but the one that I know is reliable is located here:
Once you go to Kaspersky's tech support site, the TDSSKiller zip file is available for downloading.
When you execute this software, you will be able to "cure" or repair the infected driver. Remember to jot down the name of the driver for future reference--should you need to reinstall the driver from a "same-as" working computer, or your install disk if the repair is ineffective. The driver that happened to get infected on my computer was the tcpip.sys driver. This caused my win sockets to loose their ip addresses. In most other instances, less critical drivers such as HDAudBus.sys are infected. In my case, I was not through correcting my computer problems until I corrected the broken WinSock issue and loaded an earlier version of the tcpip.sys driver from: C:\WINDOWS\ServicePackFiles\i386 which I placed in: C:\WINDOWS\system32\drivers
Don't forget to reboot your computer after your repair!
Once you download TDSSKiller and cure/repair your infected driver(s), the redirect on google searches should disappear .