Several computer trojans, disguising themselves as video or picture files related to the recent Japanese earthquake and salt stocks, have spread widely in China, a Beijing-based Internet security firm said yesterday.

Computers will be infected if users open such files through e-mails, online chatting tools and social websites. User information of bank account, online game account and privacy will be stolen by hackers through the virus, according to Beijing-based anti-virus firm Rising.

The files come with names like "Japanese earthquake update" or "salt stock information," presently much in the news.

In most cases, such files look like picture or video attachments, experts said.

Days after a 9.0-magnitude earthquake rocked Japan, triggering a tsunami and later a nuclear crisis, rumors circulated across China about how salt, which contains iodine, could prevent sickness from nuclear radiation exposure.

It caused panic buying, resulting in a shortage of salt for a short period in China.