If you take your Internet access for granted

You might wake up one day in July to find that you can no longer connect to the online world.

No, the Internet itself isn’t going anywhere. But, systems compromised by DNS Changer will find that their computers no longer know how to reach the web.

DNS Changer is malware. It originated a number of years ago, and–as the name implies–it changes DNS.

What’s DNS? OK. Let’s take a step back for a brief explanation.

DNS stands for Domain Name Service (or Server). In a nutshell, computers don’t speak English and they have no idea what “pcworld.com” or “microsoft.com” is. The way information is routed across the Internet is by IP address, and DNS is the translator that converts the Web destination to its associated IP address so the content from “pcworld.com” can magically show up on the display.

The DNS Changer malware hijacked the DNS settings of compromised computers. The Web requests would go to the DNS Changer servers, and instead of translating to the actual IP address of the site, DNS Changer would send victims to other websites instead. These other websites might phishing sites trying to dupe users out of personal or sensitive information, ad spam sites that generate revenue for the attackers simply from the traffic from the compromised systems, or malicious sites that infect the computers with other nasty stuff.

There are an estimated 350,000 systems online that still rely on the DNS Changer botnet servers for DNS services, and those servers will be shut down on July 9.

More Information from PCWorld.com: Why Your Internet Might Disappear