By CNN Money's Charles Riley
An American cybersecurity firm has linked one of the world's most prolific groups of computer hackers to the Chinese government, saying in a new report that an extensive cyber-espionage campaign is being waged from a location near Shanghai.
The security firm, Mandiant, detailed the allegations in a 60-page report published Tuesday that describes the group's tactics and history over a six-year period.
The Virginia-based Mandiant, which helps companies detect and respond to cyber threats, said it has observed the group of hackers - called the "comment crew" - systematically steal hundreds of terabytes of data from at least 141 organizations across 20 industries worldwide since 2006.
Mandiant claims the activity can be traced to four networks near Shanghai - with some operations taking place in a location that is also the headquarters of Unit 61398, a secret division of China's military.