How do I report an undetected threat file I received?

First let me say, I didn't open the file, so I'm only 99.99% certain it's a virus.  It's name is "report_3482736.doc.exe" and only a fool would open an executable with ".doc" preceding the true ".exe" extension for obvious reasons.  Regardless, Norton doesn't see this file as a threat, so I'd like to upload the original file (a ZIP file named "report_3482736.doc.zip".) to have Symantec add it to their signature system to make sure other users don't get infected.  And I'm not attaching it here.