Chinese Foreign Ministry spokesperson Wang Wenbin. Photo: VCG

Relevant companies and media should be responsible to ascertain cyber-security cases, Chinese Foreign Ministry said Wednesday, referring to Microsoft after the company alleged that a China-linked cyber espionage group had been remotely plundering email inboxes.

Citing sources from Microsoft and outside researchers, Reuters reported that a China-linked cyber espionage group had been remotely plundering email inboxes using freshly discovered flaws in Microsoft mail server software.

"China firmly opposes and crackdown on any form of cyber-attacks and cyber theft in accordance with law, and this position has always been clear," Wang Wenbin, a spokesperson of Chinese Foreign Ministry, said on Wednesday.

"Cyberspace is a difficult place to track a source, it is a complicate technical matter, and linking cyber-attacks with governments is a highly sensitive political matter," Wang said.

"We hope that the media and enterprises will adopt a professional and responsible attitude and base their judgment of cyber issues on sufficient evidence rather than baseless speculation and accusations," he added.