It’s been said that DNSChanger is one of the most prolific malware attacks in history. At its peak it infected many millions of computers, belonging to people all around the world. It uses malicious DNS servers that automatically and involuntarily convert the DNS settings of infected computers, then uses that control to redirect valid URLs to malicious sites. So if you or someone you know is infected, you effectively have zero control over Internet navigation and can’t trust that the websites you’re visiting are legitimate. Some reports claim that more than half of the Fortune 500 companies showed signs of infection and it’s said that the Estonian crime ring operating DNSChanger profited $14 million in stolen funds.

Law enforcement outsmarted the people behind DNSChanger and took over operation of the malicious servers late last year. After multiple extensions, they’ve announced a firm date of July 9 for when they’ll cease operation. On that date, the nearly half-million people still infected will not be able to connect to the Internet. And they’ll likely have no idea why.

We recently put our heads together with our friends from Cloudflare to see how to better warn infected users that their Internet would effectively break on July 9th. While OpenDNS’s services reach individual Internet users in 1 in 3 U.S. public schools, Fortune 10 enterprises and hundreds of thousands of homes around the world, CloudFlare’s service secures and accelerates hundreds of thousands of websites. Recognizing we’re collectively in a unique and opportune position to both help get the word out and guide people safely over to OpenDNS’s secure, fast and reliable DNS servers, OpenDNS has partnered with CloudFlare to deliver a solution. Think of this as a sort of Internet “Emergency Broadcast System” that leverages CloudFlare’s large reach across the web to communicate a message to those infected with DNSChanger, and OpenDNS’ ability to help protect those users.

Here’s how it works: