A U.S. Internet security company said a Chinese hacking group that has attacked U.S. and European aerospace and communications companies is almost certainly linked to the Chinese military.

In a 62-page report, California-based CrowdStrike said “Putter Panda” has been active for several years, and a trail of Internet postings and domain registrations by one of its members points to it being part of Unit 61486 of China’s People’s Liberation Army.

The link between the attacks and the Chinese army, according to CrowdStrike, was established through a number of Internet postings, photo uploads and domain registrations.

“They are roughly equivalent to the other actors we’ve seen coming out of China,” said Adam Meyers, CrowdStrike’s vice president of intelligence. “They’ve got a whole bunch of custom stuff they have built, a lot of different tools, and they have some degree of capability.”

“We see a lot on the ground, where we see first hand the intellectual property theft taking place. We really wanted to put this story out there to say it isn’t a one-off in terms of the U.S. government’s indictments. It’s a sustained, coordinated and systematic campaign against companies around the globe.”