PLA soldiers
Chinese People"s Liberation Army (PLA) navy sailors stand in a line and wait to attend a ceremony at the Great Hall of the People in Beijing, July 19, 2012. (Reuters)

China's industrial espionage using sophisticated computer malware continued unabated even after the United States exposed these attempts earlier this year, a new report by a Congressional advisory panel has revealed.

Cyber security company Mandiant had identified that a unit of China's military had carried out extensive hacking missions on a wide range of industries, mostly in the US.

Hacking attempts had diminished in volume in the immediate aftermath of the exposure of the role of Shanghai-based Unit 61398 of the People's Liberation Army in the intrusions.

However, this disclosure failed to stop cyber intrusions by the PLA unit, the US-China Economic and Security Commission, a panel which advises the U.S. Congress on China policy, has said, according to Reuters.

"There are no indications the public exposure of Chinese cyber espionage in technical detail throughout 2013 has led China to change its attitude toward the use of cyber espionage to steal proprietary economic and trade information," the commission said.

Reuters said it has seen the draft of the report, which will be published in final form a month later.

According to the latest report, the Unit 61398 only merely changed its cyber tools and infrastructure in order to make future intrusions harder to detect and attribute.

PLA Unit 61398 had stolen hundreds of terabytes of data from at least 141 organisations mostly in the United States, Canada and Britain, the report had shown.

Within a few weeks of the February report, the hacking levels from China had returned to about the same levels, a Mandiant spokeswoman told Reuters.

"From what we can tell, they are still stealing the same type of data from the same industries."

However, Chinese embassy in Washington denied the allegations, sticking with its response to the initial report.

"Cyber attacks are transnational and anonymous ... We don't know how the evidence is collected in this report," spokesman Geng Shuang said.

"China stands against cyber attacks and has done what it can to combat such activities in accordance with Chinese laws and regulations."

China had angrily responded to revelations in top secret files leaked by NSA whistleblower that the US had engaged in extensive eavesdropping, including on dozens of world leaders.

China's official press agency, Xinhua, had said Americans were "deceitful and prevaricating", and that bugging allies was their "main addiction".