DNSChanger virus: What to do to beat it

It has been called the 'Doomsday virus' and threatens to affect the internet access of thousands of people worldwide. Find out how you can protect your computer.

Around 6000 Australians are set to lose their internet access from Monday because of a virus.

The DNSChanger computer virus is malware (malicious software) that has been floating around the internet since 2007.

Infected users may not have noticed a difference in their internet service until July 9, 2012. This is because the cyber criminals who set up the malware were primarily interested in manipulating the advertising displayed on your web browser.

Once the international crime circuit behind the DNSChanger virus was discovered and shut down, the FBI in the US decided to clean up the manipulated servers and keep them running - until July 9.

They did this to give affected users a chance to remove malware and restore their Domain Name Server (DNS) settings.

How to check if you are infected

As many as 6000 Australians could be affected by the virus, the communication watchdog says.

If your internet has stopped working, or has slowed down significantly since July 9, 2012, there's a chance it could be affected by the DNSChanger virus.

However, your problem could also be a general internet connectivity problem. You can double-check internet connectivity with this basic test suggested by the Australian Communications and Media Authority (ACMA):

Open your internet browser and type '165.191.2.20' into the browser address line (where you would normally enter a URL). Hit enter.

If your internet is connected, ACMA's website should load.

If the webpage didn't load, try another: '173.194.68.100'.

This should load the Google search page.

Even if you are affected by the DNSChanger virus, these webpages should load. If they do not, you should check your internet connection again or speak to your Internet Service Provider (ISP).

Instructions for manually checking your computer for the DNSChanger virus can be found here.

How to repair your computer

Both ACMA and the Computer Emergency Response Team (CERT) suggest you run a repair tool to try to get rid of the malware.

A list of tools and resources that may help with DNSChanger detection and removal can be found here and here.

If you are confident manipulating your computer's settings, you can also get back online by manually updating your computer's DNS settings. For Microsoft Windows users, click here for details. Apple computer users can use this resource provided by the FBI.

A useful document on Trojan recovery can be found here.