London Guardian 
Feb 19, 2013
A secretive Chinese military unit is believed to be behind a prolific series of hacking attacks, a US computer security company has said, contradicting claims in Beijing that the government is not involved in such operations.
The report, by Mandiant, identified the People’s Liberation Army’s (PLA) Shanghai-based Unit 61398 as the most likely perpetrators of the hacking. The company said it believed the unit had carried out “sustained” attacks on a wide range of industries.
“The nature of Unit 61398’s work is considered by China to be a state secret; however, we believe it engages in harmful computer network operations,” Mandiant said. “It is time to acknowledge the threat that is originating in China, and we wanted to do our part to arm and prepare security professionals to combat that threat effectively.”
China has dismissed the allegations as “groundless”, saying it strictly outlaws the practice, and says it has also been a victim of such crimes.