TIANJIN - More than half of the computers in China are infected with viruses and the number is growing for the first time in 5 years, a recent survey has found.

China's computer virus infection ratio grew by 9.8 percent year on year in 2013 after reported decline for five consecutive years, the National Computer Virus Emergency Response Center said in a report on Tuesday.

A survey by the center revealed 54.9 percent of computers examined had viruses.

Online banking and online payment remain top targets for computer viruses, with hackers not only stealing money, but private information as well. Users on microblogging website Weibo were also vunerable to virus attacks, the report said.

More than half of the government website portals investigated were susceptible to cyber attack. A total of 1,367 out of 2,714 government portals examined in 2013 reported security loopholes.

Distorted web pages, spam emails, and network theft were the biggest cyber threats last year.

Chen Jianmin, executive deputy director of the center, said the security loopholes also revealed a lack of website administration and net security technologies in several organizations.

"Some internal computers were left unprotected from hackers," Chen said.

More attention should be attached to the security problem of government websites besides their service function, Chen said.