Flights of the remotely piloted armed aircraft continue worldwide.
Officials refused Saturday to provide any further details concerning what they know or don't know about the virus. They would not say whether they have any firm leads about who may be responsible responsible for planting it.
No one would or could say whether the virus is confined to those computers at Creech Air Force Base in Nevada, where pilots remotely control Predator and Reaper drones in places like Iraq and Afghanistan.
According to US officials, CIA drones that are flown over Pakistan, and most recently in the Hellfire missile strike that killed radical U.S.-born Muslim cleric Anwar al Awlaki in Yemen have not been infected by the virus.
Wired magazine reported Friday that the spyware has resisted efforts to remove it from the computers in the cockpits at Creech AFB.
The story said there are no confirmed reports that classified data was stolen and that the virus did not stop pilots from flying any of their missions.
Below is an official statement attributed to the Air Force:
"We do not discuss specific vulnerabilities, threats, or responses to our computer networks, since that helps people looking to exploit or attack our systems to refine their approach. We invest a lot in protecting and monitoring our systems to counter threats and ensure security, which includes a comprehensive response to viruses, worms, and other malware we discover."