Hackers compromised companies in more than 30 countries with the aim of gathering information on individuals in government, law-enforcement and politics, according to a report from Investigators at U.S.-Israeli cyber firm Cybereason.

Cybereason’s chief executive, Lior Div, told Reuters that the hackers used tools that have been attributed to China by the United States and its Western allies.

“For this level of sophistication it’s not a criminal group. It is a government that has capabilities that can do this kind of attack,” he told Reuters.

According to Cyberreason, the persistent attack targeting global telecommunications providers carried out by a threat actor using tools and techniques commonly associated with the Chinese-affiliated threat actor APT10.

The multi-wave attacks focused on obtaining data of specific, high-value targets and resulted in a complete takeover of the network.

Cybereason declined to name the companies affected or the countries they operate in, but people familiar with Chinese hacking operations said Beijing was increasingly targeting telecommunications firms in Western Europe.