You may have heard the reports that something called DNSChanger is expected to hit on July 9, but not known what it was or what to do.

First, what is a “DNS” and why do you care if it gets changed?  First, DNS stands for Domain Name System and it is the directory system that allows computers to locate one another.  Your computer has no understanding of a web address such as  So, after you type that into your web browser, the computer goes to the DNS and asks for the URL to be translated into something it understands.  That something is called an IP address.  Like your home address, an IP address is made up on multiple parts.  Your home address has a street number, a street, a city, state, country (perhaps) and some code, such as a zipcode.  Similarly, the IP address has a series of components that identify a specific computer uniquely.  These addresses are of the form, where the first number indicates your domain and the last number identifies a specific computer in the domain;  the intermediary numbers are further demarcations of the location.

Without a DNS server, we would all need to type in the specific IP address.  Clearly that is not practical. So, if the malware has infected your computer, then on Monday you will no longer be able to type in a URL and have your computer understand how to direct the browser.

How did that malware get put on people’s machines?  Like most malware, it infected people’s machines when they clicked on some advertising link that downloaded software to computers without the user knowing about it.  Since the software was not causing any problems, people do not know that it is on their machine — until July 9.  (Of course, with regular malware checks, this would probably have been detected.)

To avoid a problem, check your system now.  Some services, such as Comcast, has notified the users whose machines seem to be infected.  Similarly, Google and Facebook may be posting a warning if they detect your computer is infected.  To check, go to and follow the directions for checking and repairing your machine if necessary.  Do it today so you don’t have a problem on Monday!