WASHINGTON, U.S. - Chinese government hackers had been blamed by U.S. officials for leading a cyberattack on a U.S. Navy contractor earlier this year.
The U.S. Navy, which has launched an investigation into the cyberattack, along with assistance from the Federal Bureau of Investigation, said that the breach resulted in the theft of a total of 614 gigabytes of data - considered to be highly sensitive and involving U.S. security plans.
U.S. officials revealed this week that the attack took place in January and February this year.
They said that the stolen data included plan to develop a supersonic missile project as part of which, an anti-ship missile system is set to be installed on U.S. submarines by 2020.
Officials added that the hackers had targeted a contractor linked to a U.S. military organisation that conducts research and development for submarines and underwater weaponry.
A report in the Washington Post further quoted U.S. officials as saying that the U.S. Navy contractor that was targeted had been working for the Naval Undersea Warfare Center, which is a military organization based in Newport, Rhode Island.
The contractor reportedly held the sensitive data on an unclassified network.
Officials added that the material accessed by the hackers included information held within the navy submarine development unit's electronic warfare library and was related to a specific project called ‘Sea Dragon,’ which has been shrouded in secrecy ever since its launch by the Pentagon in 2012.
The Pentagon has only revealed that the project is aimed at adapting existing U.S. military technologies to new applications.
The Defense Department has said that the project will introduce a "disruptive offensive capability" by "integrating an existing weapon system with an existing Navy platform."
Since late 2015, the Pentagon has requested or used more than $300 million for the project and has said it plans to start underwater testing by September.
Meanwhile, on Saturday, officials said that the data was said to have been classified as ‘highly sensitive’ due to the nature of the technology under development and links to military projects.
Further, signals and sensor data, submarine radio room information relating to cryptographic systems was also accessed by the hackers.
Following the incident, Bill Speaks, a commander of the U.S. Navy said in a brief statement, “There are measures in place that require companies to notify the government when a 'cyber incident' has occurred that has actual or potential adverse effects on their networks that contain controlled unclassified information."
Speaks added, "It would be inappropriate to discuss further details at this time.”
He added, “Evolving cyber threats are serious matters and we are continuously bolstering our cybersecurity culture by focusing on awareness of the cyber threat, and the adequacy of our cyber defenses and information technology capabilities.”
After the incident was reported late last week, the Pentagon Inspector General’s office said that U.S. Secretary of Defense Jim Mattis had ordered a review into possible cybersecurity issues relating to the contractor.
According to investigators, the hack was carried out by the Chinese Ministry of State Security, which is a civilian spy agency responsible for counterintelligence, foreign intelligence and domestic political security.
Investigators added that the hackers operated out of an MSS division in the province of Guangdong, which houses a major foreign hacking department.
Officials said that the Pentagon’s Damage Assessment Management Office had conducted an assessment of the damage.
This is not the first time the U.S. military has suffered a cyberattack linked to Chinese hackers.
The Pentagon has previously said that Chinese Government-backed hackers have swiped crucial data on the new F-35 stealth fighter, the advanced Patriot PAC-3 missile system, the Army system for shooting down ballistic missiles known as Terminal High Altitude Area Defense; and the Navy's new Littoral Combat Ship, a small surface vessel designed for near-shore operations.
The recent breach, officials said, was part of China's long-running effort to blunt the U.S. advantage in military technology, as it aspires to become the preeminent power in east Asia.
Earlier this year, Director of National Intelligence Daniel Coats testified that most of the detected Chinese cyber-operations against U.S. industry focus on defense contractors or tech firms supporting government networks.