Chinese police said on Tuesday they have launched an investigation into a cyberattack on a technology company in Guangzhou, Guangdong province, calling it a large-scale, organized assault by an overseas hacker group.

The public security bureau in Tianhe district said the attack bore clear characteristics of cyberwarfare and was far beyond the capabilities of ordinary hackers.

A preliminary investigation showed the attackers bypassed the company's network defenses, infiltrated the back-end systems of its self-service devices and uploaded malicious software to take control of multiple network devices.

The incident caused hourslong service disruptions to the company's website and some of its business systems, resulting in significant losses and raising concerns over possible user data breaches, police said.

Authorities said the hacker group had long used open-source tools to scan, probe and exploit vulnerabilities in the networks of key Chinese departments, sensitive industries and tech enterprises, aiming to steal data and disrupt operations.

Police said the latest attack not only harmed the legitimate rights of the Guangzhou company, but also posed a serious threat to China's cyberspace order and the public interest. Authorities pledged to crack down on such activity in accordance with the law.