From January to April, Du's team received 227 security complaints from overseas and dealt with 97 cases involving fake websites.

Some government administrations should enhance awareness of online security "to avoid ignorance when we remind them of online threats to their websites", he said.

Many Chinese websites and databases also have big security loopholes and lack security testing from source, providing an opportunity for hackers, he said.

Programmers and operators should carry out security tests and risk evaluation before launching a website or product, but most fail to do so, he said.

"We have found only a small number of online threats, because many others are hidden too well to be discovered and our ability to monitor is not strong," he said.

Du said his team can coordinate with departments to cope with the threats. "It's impractical to set up a single united platform to respond to all incidents across the country," he said.

Zeng Xinhua, a criminal law researcher at Beijing Normal University, said international cooperation is crucial in handling cybersecurity problems, although difficulties remain.

"Cybersecurity management systems and laws in different countries make cooperation difficult," he said. "It is hard to balance each party's interests."

Yang Shuo, an online security specialist with more than 10 years' experience, said most cooperation is based on technologies, such as sharing the latest data.

"If governments do not trust each other, international cooperation will remain difficult and the dream of a safe cyberworld will continue to be a dream," he said.