Security firms brought in to investigate the attack discovered computer code and patterns similar to those used in previous operations by Chinese actors.
The hackers are believed to have been working for China's Ministry of State Security, the Times reported, citing sources who had been briefed on the investigation's preliminary results.
China has reportedly been trying to build a database containing U.S. government officials' personal information.
According to Business Insider, for example, the Trump administration plans to declassify United States intelligence reports that reveal China's efforts to build a database with the names of U.S. government officials with security clearances.
The official said investigators were particularly concerned about the data breach because Marriott is used frequently by the USA military and government agencies.
If investigators confirm that China was behind the attack, that could complicate already tense relations between Washington and Beijing, amid an ongoing tariff dispute and USA accusations of Chinese espionage and the theft of trade secrets.
The hack attack against the systems of the Marriott's Starwood Hotel brand saw some 500 million customers affected and threw the company under some heavy scrutiny. -China relations. The Trump administration has been working with Chinese officials to negotiate an end to the trade war.
The Marriott hacking is not expected to be part of the coming indictments.
The United States is also seeking the extradition of the chief financial officer of Chinese tech giant Huawei.
The New York Times first reported that investigators believe the attackers likely were from a Chinese state intelligence service.
The Federal Bureau of Investigation is said to be investigating the Marriott hack.
It seems as Marriott bought itself a Chinese data breach, so to speak. "The Trump administration also plans to declassify intelligence reports to reveal Chinese efforts dating to at least 2014 to build a database containing names of executives and American government officials with security clearances".