“Our preliminary analysis indicates that foreign government involvement may be associated with this activity, and that some data was taken,” the email said. “Our highest concern is the protection of our employees, including our journalists, and their sources,” it added, saying it believed the “threat activity is contained”.

FBI Director Christopher Wray said in a speech this week that the bureau opens investigations tied to suspected Chinese espionage operations about every 12 hours, and has more than 2,000 such probes. He said Chinese government hackers have been pilfering more personal and corporate data than all other countries combined.

While state-backed Russian hacking tends to get more headlines, US officials say China has been stealthily stealing far more valuable commercial and personal data over the past few decades as digital technology took hold.

Major newsrooms, including The New York Times, against which a Chinese cyber-espionage operation was uncovered in 2013, have previously been compromised.

On Sunday, March 28 last year, a major cyber attack hit the broadcast systems of Nine Entertainment, publisher of this masthead. While some experts said the attack looked like it had been launched by a state-based actor, no country or entity was identified as a suspect.

A spokesperson for the Chinese Embassy in Washington did not immediately return an email seeking comment.

The reported onset of the News Corp hack — February 2020 — coincides with Beijing’s revocation of press credentials of three Journal reporters based in the Chinese capital in what China’s Foreign Ministry said was punishment for an opinion piece the newspaper published.

News Corp’s assets also includes the publishing house HarperCollins, News Corp Australia and Storyful, which the email to employees said were apparently not targeted by the hackers.

AP