According to the team's report, 12,950 overseas IP addresses controlled 15,638 Chinese websites using back-door software between January and June this year.

A criminal can install malware on an online store or forum to monitor operations and transactions, and steal user accounts or passwords, Zhou said. This information can then be used in future fraud.

Some people also create fake versions of popular websites to dupe netizens into handing over money or private details.

"This is called phishing ... and is often targeted at online shopping platforms, such as Taobao (China's largest Internet marketplace), as well as banks and even popular TV shows," Zhou said.

Fraudsters recently scammed people using a fake homepage for Xingguang Dadao, a talent show on China Central Television, that asked for bank account numbers and passwords.

"We deal with several cases like this every month," Zhou said, adding that, between June to August his team handled more than 100 cases involving students and their parents being swindled by fake college-registration websites.

Despite having the world's largest number of Web users, people on the Chinese mainland are relatively unaware about online security.

According to the China Internet Network Information Center, almost 80 million of the country's 538 million netizens are primary, middle or high school students.

Ji Yuchun, also with the team's administration and operation department, said technical countermeasures currently used to protect users are unable to cope with the emerging challenges.

"We can't ignore the fact that some people hack websites for fun, but many do intend to connect and form organizations to commit attacks together for larger interests," she said.

"Also, attacks are becoming more sophisticated. Hacker industry chains have been established across the world."

Both Zhou and Ji expressed concern over the new Flame virus, which has been used to target the Middle East and, according to media reports, was developed for political purposes.

During the first half of the year, the team has handled 2,440 cases that involved working with overseas partners and are establishing links with foreign agencies.

The authority has already met twice with the East West Institute, an international think tank with headquarters in the US, to discuss how to tackle the online threat, Zhou said.

"International cooperation is essential to halt attacks and enhance security for everyone on the Internet," he said.

As well as efforts by government and official agencies, residents and online operators must be cautious when using the Internet or publishing information online, Ji said.

The team has also called for more specific rules to regulate the Internet and protect online security.

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