News Corp disclosed on Friday it was the target of a cyberattack that accessed data of some employees, with its Internet security adviser saying the hack was likely aimed at gathering “intelligence to benefit China’s interests”.

The publisher of the Wall Street Journal said the breach, discovered in late January, accessed emails and documents of a limited number of employees, including journalists, but added that cybersecurity firm Mandiant had contained the attack.

“Mandiant assesses that those behind this activity have a China nexus, and we believe they are likely involved in espionage activities to collect intelligence to benefit China’s interests,” David Wong, vice- president of consulting at Mandiant, told Reuters.

The Chinese embassy in the United States did not immediately respond to a request for comment.

“Although we are in the early stages of our investigation, we believe the activity affected a limited number of business email accounts and documents from News Corp headquarters, News Technology Services, Dow Jones, News UK, and New York Post,” company executives wrote in a letter to employees, seen by Reuters.

“Our preliminary analysis indicates that foreign government involvement may be associated with this activity, and that some data was taken.”

The company added that its other business units, including HarperCollins Publishers, Move, News Corp Australia, Foxtel, REA, and Storyful, were not targeted in the attack.

The Wall Street Journal, which reported the news first, competes with Reuters, the news division of Thomson Reuters Corp , in supplying news to media outlets.