it s one of the u.s. military s most important weapons systems playing a critical role in the fight against terror. and now there s new growing concern over the computers that concern drone aircraft. they re infected with a persistent virus but it is only part after much, much bigger threat. our correspondent chris lawrence is investigating all of this for us. chris, what are you picking up? right now, officials don t know if this virus is benign or truly doing harm. it has not stopped the pilots from actually flying the drones over their missions in places like afghanistan. but right now, they are in the midst of an investigation to find out if any secret data is being transmitted outside because of this virus. they ve become one of the linchpins of u.s. military power in war zones around the world. but a defense official confirms these drones are now flying while infected with a computer virus. military officials are more confused than panicked by this virus. noah sha