A man has been ordered held without bond on charges of spreading electronic viruses so he could gain control over military and other computers and sell access to hackers and spammers.

Authorities in California say Jeanson James Ancheta, 20, also downloaded adware programs onto some 400,000 of the infected computers, which made up a zombie "botnet," in order to profit from the placements.

Ancheta, who was arrested last week, pleaded not guilty Monday in federal court. Trial was set for Dec. 27.

Prosecutors say his programs were powerful enough to infect computers operated by the U.S. Naval Air Warfare Center in China Lake and the Defense Information Systems Agency, part of the U.S. Defense Department.

The 17-count indictment charges conspiracy, money laundering, transmission of code to a government computer and accessing a protected computer to commit fraud. If convicted on all counts, Ancheta could face 50 years in prison.

Prosecutors also want to confiscate more than $60,000 in cash, a BMW and computer equipment Ancheta allegedly used in the alleged scheme.