The most aggressive attacks on Chinese cyberspace originate from within the United States, and the US is the biggest thief of secrets in the world, Xinhua News Agency quoted a representative of China’s State Internet Information Office as saying.

From March 19 to May 18, 2,077 Trojan-horse networks or "botnet" servers originating in the US controlled 1.18 million computers in China, according to the country’s network emergency response center.

Meanwhile, 135 computers from inside the US controlled 563 phishing websites targeting China, leading to 14,000 cases of online fraud, such as theft of users' personal information, online passwords and locations, the center said.

Such fraud has inflicted significant losses on Chinese netizens and has included the theft of business secrets, according to the center.

In addition, 1,754 Chinese websites were implanted with software codes via "back-doors" by 2,016 IP addresses originating in the US, the center said.

These are considered the most dangerous threats to online security because such attacks are hard to identify by webmasters and users, the center said.

Based on the data, the US accusations of hacking against five Chinese military officers on Monday are "groundless", the spokesperson told the agency, saying China is a solid defender of cybersecurity and does not support online crimes.