China hacked a Navy contractor and secured a trove of highly sensitive data on submarine warfare - The Washington Post

The stolen material included secret plans to develop a supersonic anti-ship missile for use on U.S. submarines by 2020, according to officials. ....
https://www.washingtonpost.com/world/national-security/china-hacked-a-navy-contractor-and-secured-a-trove-of-highly-sensitive-data-on-submarine-warfare/2018/06/08/6cc396fa-68e6-11e8-bea7-c8eb28bc52b1_story.html