Chinese hackers have gained access to some of the United States’ most advanced weapons systems. According to a confidential Pentagon report obtained by the Washington Post, Chinese spies penetrated over two dozen military designs crucial to U.S. defenses, including missile defense systems, military ships and aircraft defense systems.

The report was prepared for the Pentagon by the Defense Science Board, a team of experts from government and private sector sources. It did not accuse the Chinese hackers of stealing the designs but officials told the Post that it was a part of a broad campaign of espionage enacted by the Chinese against U.S. government agencies and defense contractors.

Designs that were compromised include the advanced Patriot missile system (PAC-3), the Army's Terminal High Altitude Area Defense (THAAD) system for shooting down ballistic missiles, as well as Aegis, a ballistic-missile defense system developed by the Navy. Aircraft and ship designs were also accessed, according to the report. The Post published a full list of weapons and technologies that were listed as having been accessed by Chinese hackers, many of which form the foundation of the Pentagon's missile defense in Asia, Europe and the Persian Gulf.

Subcontractors have become a frequent target of Chinese hacks after the Pentagon enacted stricter security policies for major defense contractors, according to the Post. The Chinese government has said it does not conduct cyberespionage on the U.S., and government spokesman often say that Beijing is targeted by the U.S. in similar attacks. President Obama may discuss the alleged Chinese hacks with President Xi Jinping when they meet next month.

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