Washington: A cybersecurity firm says Chinese hackers with a history of state-sponsored espionage have intercepted the text messages of thousands of foreigners in a targeted operation.

FireEye says in a report issued on Thursday that hackers penetrated a telecommunications provider and planted eavesdropping software. It hasn’t said where the provider is located. It says some of the known targets were high value but none was a US official.

FireEye says the hackers belong to a group known as APT41 and the spyware captured messages that referenced politicians and military organisations at odds with the Chinese government.

The malware could not read messages sent with end-to-end encrypted applications such as WhatsApp and iMessage. FireEye says the hackers also stole detailed calling records.

A Chinese government representative hasn’t responded to an emailed request for comment.