Torpig is identified by McAfee as StealthMBR (http://vil.nai.com/vil/content/v_143908.htm).
There are several variants of this threat (StealthMBR.a, StealthMBR!rootkit, etc.) which can be found at http://vil.mcafeesecurity.com/vil/default.aspx.
The first thing you can do to enhance your chances of detecting and cleaning malware is to make sure both your Engine and DAT files are up to date. If this threat is not detected with the current DATs, please send us a sample for analysis, in a password-protected ZIP file (password - infected). You can find detailed instructions for how to do this at http://vil.mcafeesecurity.com/vil/submit-sample.aspx.
More technical information about this threat can be found on our blog:
Marking as 'assumed answered' due to age of thread. If you need any further assistance please don't hesitate to let us know.