If you have 10 minutes to spare, read about The Virus That Really Will Kill Your PC.

If you only have 5 minutes, the super-condensed version is that there’s a virus which may have altered your computer’s settings and if you’re infected, your web browser and email will stop working on July 9. To find out if you’re infected, visit http://www.dns-ok.us/. If the page shows up with a green background, then you’re in the clear (or at least, you don’t have this particular problem). A red background however means your internet connection will stop working in July.

The linked article is worth a read. In short, the FBI busted some bad guys who were hijacking people’s internet traffic by way of a virus that changes DNS settings. (DNS is the system that turns human-friendly address – such as www.thatblairguy.com – into computer friendly IP addresses.) For the time being, the FBI is running the DNS server the bad guys had been using, but that won’t go on forever.

The interesting question to me then is how does that web page work? Viewing the page source, there’s nothing but static HTML.

It turns out The Good Guys are taking advantage of the compromised DNS to set up an “eye chart”. If your computer is using a safe DNS system, then www.dns-ok.us resolves to an IP address where the “green light” page is displayed. But if your computer is using an unsafe DNS system (the one the bad guys put in place), then www.dns-ok.us resolves to the IP address of the “red light” page.