You can check this DNSChanger Malware simple step:- go with www.dns-ok.ca click agree button. after agree button if it's display green means your PC is not infect with DNSChanger Malware. check this information A RED banner at the top and bottom of this page indicates your computer system appears to be using a Domain Name System (DNS) that was part of the criminal infrastructure seized during Operation GhostClick. You are encouraged to consult the following Public Safety Canada document for further information: http://www.publicsafety.gc.ca/prg/em/ccirc/2011/in11-002-eng.aspx. A GREEN banner at the top and bottom of this page indicates your computer system uses a DNS which is not known to be associated with the criminal DNS infrastructure associated with Operation GhostClick. How does the checker work? The GREEN or RED banners are determined based on the DNS request performed by your computer in order to obtain the Internet Protocol (IP) address associated with DNS-OK.ca. This request is forwarded to CIRA?s DNS infrastructure by your DNS (typically provided automatically to your computer or home router by your Internet Service Provider). The IP address of your requesting DNS is compared to known Operation GhostClick IP addresses, which results in a GREEN or RED banner page. If you have any questions or need clarification, please contact a reputable computer professional.