DNS which is abbreviated as Domain name service which converts your webpage name and map it to an IP address of the server and helps forwarding traffic.
A group of crooks manage to infect millions of computers around the world with the Malware called DNS changer that changed victim computers DNS entry pointing towards hackers rouge/ dodgy DNS Servers.
This malware didn’t effect victim browsing, it just diverted users traffic via there pool of DNS servers which takes them to the website where they want to go like Google or youtube but now and then they manage to divert the traffic to malicious or fraudulent websites and exploit the victim computers, and some times manage to stop you get any antivirus updates.
FBI mange to track those hacker dodgy DNS servers and before shutting them down FBI move those services on legitimate clean servers as infected computers would have lost Internet access.
These interim DNS servers were suppose to be down by March 2012 but due to heavy rate of infection they postponed and those servers will be shutting down on 9th of July 2012.
The Federal Bureau of Investigation will shut down Internet servers that it temporarily set up to support those affected by malicious software, called DNS Changer. Turning off those servers will knock all those still infected offline
Rough estimate is there are more the 1/2 a Million users still infected with DNS changer malware
FBI Website have a list of DNS Servers that are going down on Monday 9th of July 2012
Rogue DNS Servers
188.8.131.52 through 184.108.40.206
220.127.116.11 through 18.104.22.168
22.214.171.124 through 126.96.36.199
188.8.131.52 through 184.108.40.206
220.127.116.11 through 18.104.22.168
22.214.171.124 through 126.96.36.199
To check if you are infected check your computer DNS address by issuing a command IPCONFIG /ALL
However there is another way on to check if your DNS is rouge or not check the below mentioned FBI site.