Russian cyberspies pursuing the secrets of military drones and other sensitive U.S. defense technology tricked key contract workers into exposing their email to theft, an Associated Press investigation has found.

What ultimately may have been stolen is uncertain, but the hackers clearly exploited a national vulnerability in cybersecurity: poorly protected email and barely any direct notification to victims…

“The programs that they appear to target and the people who work on those programs are some of the most forward-leaning, advanced technologies,” said Charles Sowell, a former senior adviser to the U.S. Office of the Director of National Intelligence, who reviewed the list of names for the AP. “And if those programs are compromised in any way, then our competitive advantage and our defense is compromised.”