A hacker last year was successfully able to hack into the computer system at the Jet Propulsion Laboratory (JPL) in California and steal 500MB of data.
Who did the hacking is not revealed in the inspector general report [pdf], but the report lists six different hacks of JPL’s computers going back to 2009, two of which were linked to China. It is therefore reasonable to assume that China, which routinely steals new ground-breaking technology rather than develop it itself, was the likely culprit. In addition, the timing of these hacks, from 2009 to 2017, fits well with the steady growth of China’s lunar program. If you wanted to find out how to build an unmanned probe to go to the Moon, JPL would be the ideal facility to steal the technology from.