DNS Changer is a trojan that tricks computers — both PCs and Macs — into redirecting all their Internet traffic through malicious servers.  According to Mashable,  the trojan’s creators have been stopped and arrested – but there are likely millions of computers that are still affected.
However, the big question that I’m being asked is “What’s DNS and how does DNS Changer affect me?”
If you want to know more about the DNS Changer trojan have a look at:
Essentially, DNS Changer redirects your computer’s DNS queries from your ISP’s server to one created by the trojan’s creators — essentially hijacking all Internet traffic from your machine. That way, the bad guys can send you to hacker-created websites filled with ads whenever they want.
So, it’s malware that infects your computer and when you go to access the Internet, directs you somewhere else.
If you’re concerned about being infected, you can check your computer at:
What’s DNS? And How Does It Work?
DNS is Domain Name System and it’s the enormous ‘look up table’ that maps domain names to IP addresses.
Think of your web hosting as your physical house (the street number and street name are like your IP Address)
Think of your domain name as the ‘tag’ associated with that physical house. Â (i.e Charly’s place)
Everyone will say “we’re going to Charly’s place”, but in reality they’re going to 11 Smith Street Woop Woop.
How do they know that Charly’s place is 11 Smith Street? Â Because I told them, they told friends etc etc etc.
Now, if I move to 64 Jones Place, Timbuktu, I’ll tell my friends the new address. Â And… in their address books etc, “Charly’s place” becomes 64 Jones Place, Timbuktu — but they still say “We’re going to Charly’s place” and just know where that is.
DNS is very similar. Â It is a network of computers that hold the ‘address book’. Â When I move my site from Host A to Host B, I tell one DNS server about the change. Â That server then tells it friends, who tell their friends etc.
Where does the DNS Changer Trojan come in?
DNS Changer is dangerous, because it tells your computer to get the ‘address’ of a website from a DNS server that  does it’s own mappings.  So instead of “Charly’s place” being 11 Smith Street, the malicious servers say that “Charly’s place” is at 33 Fredericks Place…. and located there is a big advertising billboard OR something far less desirable to view.
Hope that gives you a bit of an overview of why the trojan is very dangerous.
What can you do?
You need to make sure your Anti Virus software is up to date and that you are scanning your computer at least once a day. Â You should be doing A/V updates once a day to ensure that fixes are updated on your computer.
Don’t delay — do it now, and make sure you keep your anti virus and security up to date!
Thanks Charly this was very interesting. I’m not affected but it’s still great to know.