Bangalore: The software giant Microsoft said that it freed over 2 million PCs from malware attacks that was believed be used to steal more than $500 million from banks across the world, reports Times Of India.

"We definitely have liberated at least 2 million PCs globally. That is a conservative estimate," Richard Domingues Boscovich, assistant general counsel with Microsoft's Digital Crimes Unit, said in an interview.

Boscovich said that most of the infected PCs were from United States, Europe and Hong Kong. Microsoft and FBI, aided by authorities in more than 80 countries, on June 5 launched an assault taking down 1,400 malicious computer networks known as the Citadel Botnets by severing their access to infected machines. Microsoft's Digital Crimes Unit is working with its partners overseas to determine exactly how many of the Citadel botnets are still operational.

"We feel confident that we really got most of the ones that we were after," he said. "It was a very, very successful disruptive action."

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