Three Israel-based defense firms that architected the “Iron Dome” anti-missile system, which is currently protecting Israel from rocket strikes, were robbed of huge quantities of sensitive files related to the shield technology, KrebsOnSecurity reports.

The hackers, suspected to be based in China, also copied pages of details on U.S. missile technologies.

U.S. threat intelligence firm Cyber Engineering Services Inc. claims the attackers infiltrated the networks of Elisra Group, Israel Aerospace Industries, and Rafael Advanced Defense Systems between 2011 and 2012.

Among the information taken is a 900-page document that provides schematics and specifications for the Arrow 3 missile.

“Most of the technology in the Arrow 3 wasn’t designed by Israel, but by Boeing and other U.S. defense contractors,” said Joseph Drissel, CyberESI’s founder and chief executive. “We transferred this technology to them, and they coughed it all up.”

Read the rest at ThreatWatch, Nextgov’s regularly updated index of cyber breaches.