Have you tried sandboxing it? usually a sandbox can show you all modifications made and also reveal any incoming/ougoing connections made by the application (including their destinations).

and if you want a new signature for it, like someone said just give it an email to several antivirus companies for research. There are quite a few that allow you to send suspicious files in for investigation and will notify you of the result. If it is a new virus, they will tag it and tell you that it is indeed a virus and not to open it. If it is not, they will tell you that it is not harmful. It is not a computer who performs the "investigation" if the file passes the heuristics scanner and then will get checked by a real person.


- ryan