China's "Great Firewall" of Internet filtering blocks those U.S.-based social networks, but Unit 61398 operators got around that by accessing them directly from the unit's system. Mandiant was able to see that Facebook and Twitter accounts were being accessed from Internet Protocol addresses connected to the unit. It's not clear whether those accounts aided in hacking or were simply for the hackers' personal use.
"These actors have made poor operational security choices, facilitating our research and allowing us to track their activities," the report says.
Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.