A Chinese Foreign Ministry spokesman Thursday rejected claims that most e-mail-based malware targeting the United States originated in China.

Symantec, an Internet security giant headquartered in California, said in its March report that individuals in China were responsible for 28.2 percent of e-mail attacks, which was cited as a major source of malware.

"Such a comment is irresponsible and has ulterior motives," Qin told a regular briefing.

Internet-based attacks, including hacking, were strictly prohibited by Chinese laws and the government was taking great efforts to fight such activities, Qin said.

In a statement issued Thursday, Symantec said its statistics came from an investigation into a specific kind of malware, which accounts for only 0.02 percent of all e-mail attacks.

"The United States, instead of China, is still the main source of malware among all the e-mail attacks," said the statement.