China's Internet users have surpassed the US population in number, and more Chinese than ever are using e-commerce and accessing the Web through mobile phones, according to official statistics.

China had 338 million Internet users at the end of last month, the most in any country, the China Internet Network Information Center (CNNIC) said late Thursday.

Chatting on message boards, cruising around social networking sites and pursuing other entertainment were among the most popular activities for Web users, the center said in a report posted on its Web site. The number of Internet users who watched videos online rose 10 percent from six months ago. More than one-fourth now shop online.

China also led the world in the number of registered Web sites, nearly 13 million, using its .cn top-level domain, the report said.

The report also showed the severity of malware and other security problems in China. Over 100 million Chinese had passwords or account numbers stolen in the first of this year, and almost twice as many experienced virus or trojan attacks, it said.

Despite the huge numbers, only one in four Chinese is already an Internet user, the report said.