Story highlights The Trump administration is stopping short of publicly confronting the Chinese government

The three charged in the Pittsburgh case are presumed to live in China

(CNN) The Justice Department on Monday unsealed an indictment against three Chinese nationals in connection with cyberhacks and the alleged theft of intellectual property of three companies, according to US officials briefed on the investigation.

But the Trump administration is stopping short of publicly confronting the Chinese government about its role in the breach. The hacks occurred during both the Obama and Trump administrations.

The charges being brought in Pittsburgh allege that the hackers stole intellectual property from several companies, including Trimble, a maker of navigation systems; Siemens, a German technology company with major operations in the US; and Moody's Analytics.

The three charged in the Pittsburgh case are presumed to live in China and are either employed or associated with Guangzhou Bo Yu Information Technology Co., known as Boyusec, court documents say. US intelligence and private cybersecurity experts say Boyusec works as a contractor for the Chinese ministry of state security, that nation's version of the National Security Agency. The court documents unsealed Monday don't mention the Chinese state links.

US investigators have concluded that the three charged by the US attorney in Pittsburgh were working for a Chinese intelligence contractor, the sources briefed on the investigation say. But missing from court documents filed in the case is any explicit mention that the thefts were state-sponsored.

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