http://www.wired.com/politics/security/news/2008/04/chinese_hackers

Espionage Against Pro-Tibet Groups, Others, Spurred Microsoft Patches

By Ryan Singel 04.10.08 | 6:40 PM

SAN FRANCISCO -- Computer intruders targeting pro-Tibetan groups, U.S.
defense contractors and government agencies slipped in through
previously unknown security holes in Microsoft Office, prompting
Microsoft to issue a flurry of patches to the popular software suite
in 2006 and 2007, according to computer security experts.
These attacks, which appeared to have originated in China, began in
early 2006 when the attackers started sending e-mails to victims with
booby-trapped Word documents and Excel spreadsheets attached.
"We are seeing more and more spying done with Trojans, a shift that
has happened in the last two years," Mikko Hyppönen, the chief
research officer for software security vendor F-Secure, told RSA
conference attendees Thursday morning.

The Pentagon and pro-Tibet groups have previously acknowledged the
intrusions, but Hyppönen is the first to link the cyber espionage to a
series of patches that Microsoft pushed out without explanation.
Microsoft did not immediately reply to a request for comment.