Windows

Check out the Trojan.Qhosts virus on Symantec or Qhosts1 on McAfee. I had similar problem that turned out to be this virus.

You've apparently gotten infected with the QHosts trojan. Read here for
information:

http://www.sarc.com/avcenter/venc/data/trojan.qhosts.html
http://us.mcafee.com/virusInfo/default.asp?id=description&virus_k=100719
http://www3.ca.com/virusinfo/virus.aspx?ID=37191


Try the following:

1. Be sure that you install hotfix 828750 which fixes the exploit that this
virus uses:

http://www.microsoft.com/windows/ie/downloads/critical/828750/default.asp

2. Update and run a complete Anti-Virus software check of your system. Most
of the major AV companies have updated their latest signatures to detect
this virus (for Network Associates, be sure to get the EXTRADAT.exe update
from the above page as well as your regular update).

3. If running your AV doesn't clean it up, go to this page, read the
directions CAREFULLY (particularly about the Restore option) and download
and run the removal tool:

http://securityresponse.symantec.com/avcenter/venc/data/trojan.qhosts.remova
l.tool.html

If that still doesn't clean it up (and a number of people are reporting that
it did not), then follow the Manual Removal instructions there. The
following is courtesy of Mike Burgess:

"Does a HOSTS file still exist in Windows\Help?
Trojan Qhosts hijacks the HOSTS file, however unlike normal redirectors,
this one hides the HOSTS file in the "Windows\Help" folder. It then
creates entries that redirects all major search engines to a website.
Note: this website has now been removed, thus the DNS errors.
[more info]
http://www.mvps.org/winhelp2002/hosts.htm (bottom of page)
Run the beta version of HijackThis (link on Hosts page)

Also, reset the TCP/IP settings.
Click Start | Run | Cmd
type "netsh int ip reset changes.txt"