The move made it temporarily impossible for infected PCs around the world to search the web, though the companies offered free tools to clean machines through messages that were automatically pushed out to infected computers.

Technicians working on behalf of both companies raided data centers in Weehawken, New Jersey, and Manassas, Virginia, on Wednesday, accompanied by U.S. federal marshals, under an order issued by the U.S. District Court in Alexandria, Virginia.

They seized control of one server at the New Jersey facility and persuaded the operators of the Virginia data center to take down a server at their parent company in the Netherlands, according to Richard Boscovich, assistant general counsel with Microsoft's Digital Crimes Unit.