China's Blue Army was probably involved.

From what I have picked up, if you were a Chinese expert in the DC area, you probably got targeted.  It was a spear fishing type hack, where a person is sent an E-Mail with an attachment that when opened, gave access to their computer to the hacking team.  The WSJ article has a lot of details.

And China is threatening Google for speaking out against the cyber attacks.  The challenge being that Google has moved it servers outside of China, that there is not much that China can do off against Google.

China targeted White House with Gmail hacking - as Hillary Clinton calls threat 'very serious' - Mail Online

Gmail Hack Targeted White House - WSJ.com

China Threatens Google for Speaking Out Against Cyberattacks - Daily Tech

Labels: google, US Chinese Image