This detection may be triggered when accessing suspicious web pages.
Please let BitDefender disinfect your files.
Sorin Ciorceri, virus researcher
This exploit is based on a vulnerability that affects the "DownloadAndInstall()" method of the Sina DLoader class ActiveX control. As the method name said this exploit will download and install some file which can be anything.
For more info please check: http://www.securityfocus.com/bid/30223/info