>Dmitry, the culprit may have added a false map to your hosts file, in windows\system32\drivers\etc. This may not be picked up by a virus or spyware scanner, but you can easily edit it in Notepad to remove the fake map. HTH.
This is a good idea and the easiest way to do this is to use SpyBot to add its bad address list to the host file for you. It has collected, and maintains, a large list of bad urls for this purpose.
In the End, we will remember not the words of our enemies, but the silence of our friends - Martin Luther King, Jr.