CyberESI firm revealed that Chinese hackers members of the Comment Crew group violated the corporate networks of top Israeli defense companies. Chinese hackers accessed plans regarding other other missile interceptors, including drones, ballistic rockets and the Arrow III missile interceptor which was designed by Boeing and other US-based companies. The Comment Crew was still working undercover after an apparent period of rest after the Mandiant Intelligence Center released a report on a large-scale cyber espionage campaign dubbed APT1 in February 2013. The report blamed the Chinese military unit called 61398 for a series of cyber attacks that compromised 141 organizations in seven years.”]
Source: http://securityaffairs.co/wordpress/27132/cyber-crime/comment-crew-stole-plans-iron-dome.html