China has increased its cyber espionage efforts to acquire U.S. secrets and technology, a Congressional advisory group warned in a report issued on Thursday.

Echoing its 2008 and 2007 reports, which labeled China's espionage efforts "the single greatest risk to the security of American technologies," the U.S.-China Economic and Security Review Commission (USCC) said in its 2009 annual report that "there has been a marked increase in cyber intrusions originating in China and targeting U.S. government and defense-related computer systems."

Testifying before the Senate Subcommittee on Terrorism and Homeland Security on Tuesday, USCC vice chairman Larry M. Wortzel said that cyber attacks on Department of Defense information systems went from 43,880 in 2007 to 54,640 in 2008, an increase of almost 20%. If attack trends from the first half of 2009 continue at the same pace throughout the year, he said, approximately 87,570 cyber attacks will be recorded, an increase of 60% from 2008.

Responding to these attacks can be problematic because, as the report states, Chinese espionage and cyber espionage activities may be carried out by individuals without obvious government ties.

These "nonprofessional collectors may be motivated by profit, patriotism, feelings of ethnic kinship, or coercion," the report states. "Even in many cases where there is no obvious direct state involvement in the theft or illegal export of controlled technology, the Chinese government encourages such efforts and has benefited from them."

The report also refers to these individuals as "espionage entrepreneurs."

Wang Baodong, spokesperson for the Chinese Embassy in Washington, told the BBC that the report's claims about Chinese espionage are "baseless, unwarranted and irresponsible."

In April, the White House said that it would establish Cyber Security Coordinator position to manage cybersecurity activities across government agencies. That position has yet to be filled.