The FBI has uncovered a network of rogue DNS servers and has taken steps to disable it. Both Windows and MacOS users are at risk for this infection because it exploits your browser, not your operating system. The FBI is also undertaking an effort to identify and notify victims who have been impacted by the DNSChanger malware. After the take down of the DNSChange Botnet, in November 2011, the FBI obtained a court order allowing the FBI to set up a temporary DNSChangers Command & Control network. The court order expires on March 8th, 2012, resulting in millions of computers, world-wide, no longer being able to access the Internet.
Source: https://thehackernews.com/2012/02/faq-dnschanger-trojan-impact-and.html