You can also check through this website, http://www.dcwg.org/ , which was set up by the DNS Changer Working Group .
According to the FBI, the number of computers that probably are infected is more than 277,000 worldwide, down from about 360,000 in April. About 64,000 still-infected computers are probably in the United States.
The Canadian Internet Registration Authority said about 25,000 of the computers initially affected by the malware were in Canada, but now only about 7,000 machines remain infected there, according to Canadian Internet Registration Authority spokesman Mark Buell.
He said his organization, together with Public Safety Canada and the Canadian Radio-television Telecommunications Commission, has developed an online site where computer users can check their computers for the malware.