Justin Henkel, now CISO of IT monitoring company SolarWinds and formerly an IT security officer for the Air Force, described the practice in a recent interview. He said that before USB drives became common, pilots burned mission data onto CDs that were then loaded into both unclassified and classified systems as well as into aircraft to assist navigation and threat awareness. When thumb drives arrived, pilots began using them the same way.
“They didn't really think about the overall impact of classified versus unclassified systems,” Henkel said. “Using the same device for both, they didn't understand that you could read and write onto a USB drive with malware. [They were] not really understanding the overall threat picture.”
Compounding the risk, personnel often bought flash drives from local vendors rather than military suppliers. In Afghanistan, Henkel said that meant “going out into the local market in Kabul” and building relationships with vendors. “Hey I need 100 USB sticks,” he recalled.
Henkel said he raised concerns as a junior officer but was ignored. “I was a young 22-year-old guy, very junior in the overall rank system, trying to tell colonels and majors that what they're doing is a violation.”
The vulnerability was exploited in 2008 when an infected USB drive was attached to a laptop with access to US Central Command. The resulting worm, Agent.BTZ, could collect data and communicate with remote servers. A 2016 report from the FBI and DHS attributed the malware to Russian groups. It took the Pentagon 14 months to scrub the worm and led to a ban on USB drives that same year. The drives were permitted again under restricted conditions in 2010.