Wait, what's going on tomorrow?

You're probably hearing about "DNS changer", a worm/virus that is getting a lot of hype right now because of something the FBI is doing tomorrow.  I'm going to break this down for you, but first a quick lesson.

DNS stands for "Domain Name Service", and it is the way that computers find each other.  You see, computers don't work with human readable names, so in order for your computer to find the servers at, say, NickSimmonds.com, or Google.com, your computer takes the address that you type (or that you're linked to) and then looks it up against a table of numbers.  First, it checks its own database to see if it's got a recent record of that site.  If it doesn't, it contacts your "DNS server", to see if that server has a record.  If that server doesn't, it sends the request on up the chain until it gets to the internet's "root DNS servers", which are central servers that maintain the address list for the whole internet.  What it gets back is a numerical address, which it then uses to send and receive information.

You can actually see these addresses, if you'd like.  If you are comfortable opening a command prompt on a PC or a terminal window on Mac/Linux, you can use the command nslookup to find the number associated with a domain, e.g., nslookup google.com, which will give you a list of numbers because Google uses many servers.  One of those is, and if you follow that link or type it into an address bar, you'll see it takes you right to Google's main site.

What the "DNS changer" worm does is point your computer at servers that give you bad info, and then use that to control your web browsing.

Or rather, that's what it did, until some time last year, when the FBI seized those addresses and pointed them at servers they control.  Now, rather than telling people who were infected about it, or just shutting down their internet access, they let these people browse the web normally.  This is potentially a serious breach of privacy, as the FBI now knows every web site those people have been to in the past year, but it does mean that internet commerce was unaffected.

Tomorrow, however, they're shutting down this network.  If you're infected, you'll be redirected to an FBI site instead of being allowed to use the web normally until you've cleaned up your computer.

You're probably not infected by this.  All recent antivirus and antimalware programs are capable of catching and removing this thing.  If you are, you're still pretty safe, although your browsing prior to the FBI seizure was compromised and everything since has been recorded.  You'll know tomorrow.  If you'd like to check ahead of time, head here to check for infection, and follow the steps given for cleanup if you're infected.  Otherwise, just wait a day and you'll find out.

Edit:  the previous link used to go to a different spot, a server in the US, but it looks like there may be an attack currently launched against that site.  The updated link goes to a server in Canada, which seems unaffected.

This isn't much to worry about, but I do recommend everyone install something like Malwarebytes just to check their machines periodically, in addition to an antivirus program.