A fired Fannie Mae contract worker pleaded not guilty Friday to a federal charge he planted a virus designed to destroy all the data on the mortgage giant's 4,000 computer servers nationwide. Had the virus been released as planned on Saturday, the Justice Department said the disruption could have cost millions of dollars and shut down operations for a week at Fannie Mae, the largest U.S. mortgage finance company. Rajendrasinh B. Makwana, 35, of Glen Allen, Virginia, pleaded not guilty in US District Court in Baltimore to one count of computer intrusion, the US attorney's office said. Makwana's federal public defender, Christopher C. Nieto, didn't return calls seeking comment on the case. The Associated Press was unable to reach Makwana in Glen Allen, Virginia, a suburb of Richmond. A search of public records found no address or telephone number for him there.