Today marks the day that the infamous DNSChanger virus is finally shut down by the FBI in the USA. This could cause anyone that was still infected to lose their internet connection.

DNSChanger came about in early 2007. It was a simple piece of malware that changes your computer's DNS settings to redirect to the hackers' servers. DNS is required to convert the domain name of a website (ex. google.com) into the IP address of a website (ex 196.23.168.161). This was usually done by DNS servers, mostly found at ISP's or large DNS servers. The hackers made your computer redirect through their own servers, allowing them to set up click-to-earn ads. These would then be requested randomly when trying to access websites. The Estonian hackers presumably made $14m this way, according to the  Guardian

In a long struggle, the FBI and associates have finally found most of these servers, and are shutting them down on Monday, the 9th of July, which is today. This will cause the still 500k infected computers to lose internet access in sense, because they will be unable to resolve domain names.

To avoid problems, you can check the site  Detect | DCWG  to confirm that you don't have the malware. If you do, it would be prudent to get it removed quickly to avoid unnecessary complications.