Microsoft, Nominum and other companies have joined with the FBI to disrupt a global cyber crime operation using the Citadel botnet.

Its report claimed that the operation was responsible for more than $500 million in losses to people and businesses and managed to infect more than five million people.

Microsoft was able to cut off communication between 1,462 Citadel servers and seized data and evidence from the botnets yesterday, including computer servers from two data hosting facilities in New Jersey and Pennsylvania. The FBI also obtained and served court-authorised search warrants domestically related to the botnets.

Brad Smith, Microsoft general counsel and executive vice president, legal and corporate affairs, said: “Today's coordinated action between the private sector and law enforcement demonstrates the power of combined legal and technical expertise and we're going to continue to work together to help put these cyber criminals out of business.”

FBI executive assistant director Richard McFeely said that creating successful public-private relationships where tools, knowledge and intelligence are shared, is the ultimate key to success in addressing cyber threats, and was among the highest priorities of the FBI.

“We must ensure that, as cyber policy is developed, the ability of the private sector to coordinate in real-time with the FBI is encouraged so that a multi-prong attack on our cyber adversaries can be as effective as possible,” he said.