Hi, foreigner working in Chinese high tech company here. I wonder a bit, on which ground is this attack attributed to Chinese gov? It looks a bit unlikely to me. China has some cyber military but they are more likely to be pragmatic and choose wisely their targets. There's a bunch of script kiddies but they would choose also something else. However it seems possible that many servers hosted in China are not secured and could be used for this attack, by some other people.
Just my first thought as an insider...