A group of Chinese spies worked for years to hack aerospace companies and steal aircraft technology secrets, the Justice Department said today, as it announced the indictment of 10 people accused of stealing companies’ confidential information.

10 people indicted

According to the department, Chinese intelligence officers and their operatives worked to steal the technology behind a turbofan engine used in commercial airliners. The scheme allegedly went on from at least early 2010 until May 2015, and targeted an unnamed French aerospace company that was working on the engine with a US company.

Chinese intelligence officers allegedly hacked the French company, as well as aerospace companies in several states and the United Kingdom. Prosecutors said the hackers used techniques like spear phishing and malware to gain access to the confidential information.

The indictment is the third of its kind announced by the Justice Department since last month. In one case, the department accused another Chinese intelligence officer of attempting to steal aircraft engine secrets, while a US Army recruit has been accused of working on behalf of Chinese intelligence.

“State-sponsored hacking is a direct threat to our national security,” US Attorney Adam Braverman said in a statement. “This action is yet another example of criminal efforts by the MSS [China’s Ministry of State Security] to facilitate the theft of private data for China’s commercial gain.”