I was about to comment the exact same thing. It's known for years, now, that they do that. This practice is outlined in the book "Cyber War: The Next Threat to

I was about to comment the exact same thing. It's known for years, now, that they do that. This practice is outlined in the book "Cyber War: The Next Threat to National Security and What to Do About It," in which the author explains how the NSA has a profile on all (know) Chinese hackers.