An estimated 300,000 computer connections are going to get scrambled when the FBI turns off the command and control servers for the DNSChanger botnet on Monday.
The FBI took control of the botnet in November after identifying its command servers and swapping them out for their own systems – as well as arresting six Estonians accused of running the scam. But it left the botnet running, since shutting it down would have disrupted the connections of the infected systems, which at the botnet's height accounted for over four million computers.
DNSChanger reroutes DNS requests to its own servers and then pushes scareware and advertising to infected machines. Shutting it down, however, will leave computers unable to access websites and email properly without a fix being applied. The FBI had been due to shut down DNSChanger in March, but left it up for an extra three months to allow more time for users to disinfect their systems.
Companies and governments have made a big effort to clean systems with the help of the DNS Changer Working Group (DCWG), which was set up by security experts to manage the problems. But according to the latest DCWG data, there are still 303867 infected systems out there, with around a fifth of those based in the US.
Checking for infection is simple enough. Links on the FBI and DCWG site will allow users to be scanned for the malware automatically, and fixes are available for Windows systems down to and including XP. Security software vendors have had patches out almost since DNSChanger was detected, and have free tools available. The DCWG recommends using these multiple times to make sure any infection is stymied.
So who's going to be left looking at a dead connection on Monday? Security firm IID estimated last month that 12 per cent of the Fortune 500 firms and 4 per cent of "major" US government organizations still have machines infected with DNSChanger, although it noted things were improving rapidly.
No doubt many consumers will also add to those numbers, so expect a call from your aging relatives on Monday, asking why they can't make the internets work. ®