Qhosts trojan

Install the latest IE cumulative patch for protection against QHosts:
http://www.microsoft.com/security/security_bulletins/ms03-040.asp

Note: If you are already infected, installing the patch will NOT fix your problem. You have to get rid of the infection as well (see links below).

Information about the trojan can be found here:

http://www3.ca.com/virusinfo/virus.aspx?ID=37191

http://vil.nai.com/vil/content/v_100719.htm (pay close attention to the advice about HOSTS hijacking in the registry)

http://securityresponse.symantec.com/avcenter/venc/data/trojan.qhosts.html (removal tool available)

http://software.brown.edu/dist/w-cleanqhosts.html (removal tool)