BEIJING (WACH/AP) -- An Internet security company has said it traced the source of massive computer hacking attempts to a People's Liberation Army building in Shanghai .
The 60-page report by Internet security company Mandiant said the hackers have systematically stolen hundreds of terabytes of data from organizations across a broad range of industries in English-speaking countries.
The report issued Tuesday focused on 141 major hacking attempts and says the hackers targeted 20 industries, including military contractors and companies with access to energy grids.
Mandiant is the same company South Carolina hired to address the issues at the Department of Revenue after hackers accessed information on 4 million taxpayers.
This report does not identifiy specific organizations targeted by the hackers, or if they are responsible for the hack on SCDOR.
"It is time to acknowledge the threat is originating from China, and we wanted to do our part to arm and prepare security professionals to combat the threat effectively," Dan McWhorter Mandiant's Managing Director of Threat Intelligence said in a release.
China has dismissed the report as `'groundless."Foreign Ministry spokesman Hong Lei said he doubted the evidence would withstand scrutiny. He said: "To make groundless accusations based on some rough material is neither responsible nor professional."
China has frequently been accused of hacking, but says it strictly outlaws the practice and says it is itself a victim of such crimes.
You can read the entire Mandiant report here .
(The Associated Press contributed to this report.)