Ten days to the day that cyber security firm Mandiant released a blistering report on China's state-sponsored sustained hacking of the United States's vital infrastructure and top companies, the Chinese Ministry of Defense has its own report about the U.S. hacking two vital military sites. "According to the IP addresses, the Defense Ministry and China Military Online websites were, in 2012, hacked on average from overseas 144,000 times a month, of which attacks from the U.S. accounted for 62.9 percent," ministry spokesman Geng Yansheng is quoted as saying in a Reuters report. Whether or not those numbers are manipulated or not, that's a bit more specific than what China had said on February 20, in the days following the Mandiant report, when the defense ministry claimed "Chinese armed forces" were being hacked via "a considerable number of attack sources from the United States, but we did not [use this] a pretext to accuse the U.S. side."  

Is the concept of the U.S. hacking China surprising? Probably not. The U.S. recently announced the creation of a new medal, the "Distinguished Warfare Medal", which members of military cyberwarfare operations can get. And prepping for cyberwarfare defense includes offense. Back in 2009, The New York Times reported on the U.S. ramping up its offensive cyberwarfare capabilities, and former Secretary of Defense Leon Panetta told CBS last January that being aggressive was a necessity:

The reality is that there is the cyber capability to basically bring down our power grid to create ... to paralyze our financial system in this country to virtually paralyze our country. And I think we have to be prepared not only to defend against that kind of attack but if necessary we are going to have to be prepared to be able to be aggressive when it comes to cyber efforts as well. We've got to develop the technology, the capability, we've got to be able to defend this country.

Though that isn't a clear admission of going on hacking offense, owning up to "aggressive" measures is still a step ahead of China, which is still clinging to the claim that their cyberforce is "purely for defense."