"The Chinese army has never supported any hackings," the Ministry of National Defense said in a statement, adding such accusations are unprofessional and false, China Daily reported Wednesday.
Earlier, Chinese Foreign Ministry spokesman Hong Lei said the allegations against China are groundless, adding cybercrime is an international problem that should be solved through international cooperation, Xinhua News Agency reported.
The reports said the Chinese ministries were reacting to recent claims by Internet security company Mandiant about China's army controlling some of the most prolific hackers and of tracing a host of cyberattacks to a building in Shanghai.
In an investigative piece this week, The New York Times, quoting sources, reported China's growing digital hacking groups seem to be operating out of a 12-story building on the outskirts of Shanghai that is home to Unit 61398 of China's People's Liberation Army and likely the base of China's corps of cyberwarriors.
The Times said a growing body of digital forensic evidence, confirmed by U.S. intelligence officials, showed much of the attacks on U.S. corporations, organizations and government agencies appeared to originate in and around the building.
The Times said Mandiant even tracked individual members of the highly sophisticated of the Chinese hacking groups "Comment Crew" or "Shanghai Group" to the PLA unit's headquarters. The report said other security firms, studying "Comment Crew," also said they believe the group is state-sponsored.
China Daily in its reports quoted "observers" as saying verifying Mandiant's evidence would be difficult since the hackers' origins are transnational and anonymous. They said the Shanghai building trace, if true, also showed the company hacked the building.
Foreign Ministry spokesman Hong was quoted as saying last year about 73,000 overseas IP addresses controlled more than 14 million computers in China and 32,000 IP addresses remotely controlled 38,000 Chinese websites. Hong claimed attacks originating from the United States ranked at the top.
In her daily media briefing Tuesday, U.S. State Department spokeswoman Victoria Nuland said the issue of cyberthreats from China including the involvement of the military had been raised "at the highest level."