According to WIRED News, America’s fleet of Predator and Reaper drones have been hit by a computer virus that logs pilots’ every keystroke. While a source familiar with the infection, which was discovered several weeks ago, says the virus is considered “benign,” network security specialists can’t seem to wipe it from the computers at Creech Air Force Base in Nevada.

It is unclear exactly how the keylogger came to reside on the drones’ systems, whether it was intentional or accidental. There is the possibility that it’s just a common piece of malware that “just happened” to find its way into the systems. Wired blogger Noah Shachtman says the virus is believed to have spread through removable drives, which Predator and Reaper crews use to load map updates and transport mission videos from one computer to another. Regardless, it has been resistant to numerous attempts to remove it.

It also is unclear just how far the virus has spread, although it is certain that it has infiltrated both classified and unclassified machines at Creech, raising the possibility that secret data may have been captured and leaked to someone outside the military chain of command. However, the virus is not keeping the drones grounded, reports Reuters, as they continue to fly remote missions overseas.

Unsurprisingly, the Air Force is remaining tight-lipped about the incident, releasing this statement posted by msnbc.com:

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.

That response isn’t likely to quell the concerns of some security experts like Richard Stiennon, chief research analyst with IT-Harvest in Birmingham, Mich. Stiennon told PCWorld.com:

This is bad in so many ways. It indicates that the military is using completely insecure operating systems and practices for the critical function of controlling drones …These are deadly weapons that must work as required and only when required. To have their command and control corrupted by apparently common malware is inexcusable.