A previously undisclosed portion of a U.S. Defense report lists the specific weapons system designs that it says have been at least partially compromised by Chinese hackers -- from the most advanced fighter plane in history to America's missile defense systems.
The list of weapons, first reported Monday by The Washington Post and confirmed to ABC News by a U.S. official, was included in a version of a report from the Department of Defense's Defense Science Board (DSB) made for top Pentagon and defense industry officials. The board released a public version of the report in January.
Among the more than two dozen major weapon systems listed in the report are the stealth F-35 Joint Strike Fighter aircraft program, the most expensive weapons program in history whose breach was previously reported; the Global Hawk long-range surveillance drone; aspects of the Patriot missile system; the Navy's Littoral Combat Ship and Black Hawk helicopters. Information on various U.S. government technologies was also siphoned by cyber spies including nanotechnology, directed energy, space surveillance telescopes, tactical data links and drone video systems.
The DSB report did not accuse the Chinese of stealing the designs, but the U.S. official told ABC News Chinese hackers had obtained the information by accessing the networks of private defense companies that do business with the Pentagon. It was unclear the extent of the Chinese penetration, the official said.
"...[T]he cyber threat is serious and... the United States cannot be confident that our critical Information Technology (IT) systems will work under attack from a sophisticated and well-resourced opponent utilizing cyber capabilities in combination with all their military and intelligence capabilities," the public version of the DSB report said. "This conclusion was developed upon several factors, including the success adversaries have had penetrating our networks..."
Pentagon spokesperson George Little addressed the report today, saying the Defense Department maintains "full confidence in our weapons platforms."
"Suggestions that cyber intrusions have somehow led to the erosion of our capabilities or technological edge are incorrect," he said.
The report comes as White House National Security Adviser Tom Donilon met with high-level Chinese military officials at the Chinese Defense Ministry, where he reportedly called for a "new model for relations" by "ensuring we have a healthy, stable and reliable military-to-military relationship."
In March Donilon said in a speech that Chinese hacking was at the "forefront of our agenda" and asked China to "put a stop to these activities," but in the recent meeting, the topic of cyber attacks did not come up, Reuters reported. The White House said President Obama plans to discuss the matter with Chinese leader Xi Jinping at a meeting in June.
The revelation about the weapons systems hack came the same day an Australian news outlet reported Chinese cyber spies managed to steal the plans for that nation's new $600 million-plus intelligence headquarters. The blueprints included details on communications cabling, server locations and security systems, the report said.
The Chinese government has repeatedly called hacking accusations "groundless" and has claimed to be the victim of a widespread American cyber espionage campaign.
Richard Clarke, a cyber security expert and ABC News consultant, said he was not surprised at the weapon systems that were targeted, but said the danger from Chinese hackers is "very much a major concern" for the U.S. government for three reasons:
First, he said that by just stealing technological secrets, the Chinese military is saving billions of dollars on research and development costs for their own systems. He pointed to the apparent similarities between advanced U.S. systems -- like the stealth F-35 Joint Strike Fighter -- and new Chinese programs -- like their J-20 stealth fighter, as well as strikingly similar drone platforms.
Second, Clarke said the government is concerned the Chinese could use the stolen information to find vulnerabilities in the American military assets.
As Frank Cilluffo, director of George Washington University's Homeland Security Policy Institute, put it, the Chinese want to "discover the Achilles heel of our weapons systems and defenses."
Lastly, Clarke said there is concern the Chinese may have been able to penetrate the supply chain for major weapons systems and installed cyber back doors in the components before going into the final weapon system.
John Pike, Director at GlobalSecurity.org, told ABC News it's unlikely the most sensitive information about the weapons programs was stolen because that information resides on Pentagon servers, not with the private companies that have allegedly been hacked. He also said that in some cases China is so far behind in developing similar technology that "even if they did acquire the most technically sophisticated data, I'm not sure they'd know what to do with it."
But Cilluffo pointed out another, more specific potential impact the breach may have in the Pacific.
There, he said, Secretary of Defense Chuck Hagel has ordered America's Theater High-Altitude Area Defense (THAAD) missile defense system to Guam in response to recent North Korean missile tests. The THAAD system is listed among those compromised by the Chinese hackers, raising the possibility that any compromising information on the advanced system could be shared between the friendly Asian nations.
Lockheed Martin, America's largest defense contractor, said in a statement to ABC News that the company "remains confident in the integrity of our robust, multi-layered information systems security."
A representative for another major defense contractor, Northrop Grumman, declined to comment on the allegations agains the Chinese, but said they've seen the number of attempts to breach our networks "increasing at an alarming rate."
Boeing declined to comment and directed all inquiries to the Defense Department.