Liang Hong, director of the National Computer Virus Emergency Response Center, has told China's netizens to beware of viruses during the upcoming holiday season.

A virus called "MSNMSG.A" was originally spotted in OICQ, a Chinese instant message software, and can easily pass through Microsoft's MSN system. Users are urged to update patches on their software and to not open messages from unknown sources.

Other viruses on the center's list also include "W97M_TNT.B", "PE_Kriz.4029" and "WM_BIBDOT.A", which will change people's computer data or encrypt Word documents with unwarranted pin numbers.