LOS ANGELES - Hackers targeted mobile phone networks around the world to snoop on specific users, according to a report.

The level of access they gained to the networks meant they could have shut them down had they wanted to.

US-Israeli security firm Cybereason concluded “with a high level of certainty” that the hackers were based in China, probably sponsored by the government.

The attack - dubbed Operation Softcell - began in 2017.

Cybereason spotted the attacks in 2018 and helped one telecoms provider through four more over the next six months. It has now briefed more than a dozen others.

None of the targeted firms or people has been named but, according to the report, the hackers collected the call records and geo-location of various individuals from a selection of countries, including those in Europe, the Middle East and Asia. The security firm identified changes in the pattern of attack and new activity every three or four months. The hackers gained entry to networks via a flaw in a web server product.

Cybereason said the tools and techniques bore the hallmarks of Chinese hacking group APT10, which is widely believed to operate on behalf of the Chinese government.

Security expert at the University of Surrey, Prof Alan Woodward said the scale and audacity of the attacks was “breathtaking”.