A Chinese national was sentenced Wednesday to nearly four years in prison for plotting with Chinese military officers to hack computers belonging to U.S. defense contractors such as Boeing Co. and obtain trade secrets involving designs of American military aircraft.

In addition to the prison term, U.S. District Judge Christina A. Snyder ordered Su Bin, a 51-year-old man who is also known as Stephen Subin and Stephen Su, to pay a $10,000 fine.

Bin, who operated an aviation and aerospace company in Canada, pleaded guilty March 23 to a federal conspiracy charge of gaining unauthorized access to a protected computer. He was arrested in British Columbia in 2014, and he waived extradition to the U.S. in February 2016.

Starting in 2008 and continuing until 2014, Bin informed military officers in China about what sites to hack and which files to steal, and he advised his co-conspirators on which information was significant, according to the U.S. attorney’s office in Los Angeles.

Bin did not get any money from the scheme, but he admitted that he entered into the plot in order to profit.

One of the companies targeted in the conspiracy was Chicago-based Boeing, whose computer servers in Orange County stored detailed files on the C-17 military aircraft. Bin admitted that sensitive military information was accessed on the servers and sent to China, according to a plea agreement filed in the Central District of California.

Bin and his co-conspirators also handled data related to the F-22 and F-35 fighter jets, both made by Lockheed Martin Corp., according to court papers.

Read More: LA Times