Detect DNSChanger and Notify Visitors
Using This Tool
The easiest way is to put your site on CloudFlare and go to https://www.cloudflare.com/apps/dnschanger_detector to enable the app.
How It Works
DNSChanger Detector works by attaching an alerting function to the window, and making a JSONP call to a special URL. The IP resolved for that URL by the infected servers serves a file that calls the alerting function.
The alert is banner at the top of the page with information about how to fix the infected computer. It looks like https://www.cloudflare.com/images/apps/dnschanger_detector/banner_example.png
For Non-CloudFlare Sites
CloudFlare is trying to make the Internet better for everyone.
The Federal Bureau of Investigation (FBI) has been operating DNS servers to keep infected users online, but they are going to stop soon (July 9, 2012). We want to do what we can to keep people from being kicked off the Internet when that happens.
For more background, see http://www.fbi.gov/news/stories/2011/november/malware_110911