SI data base does not contain the Direct download link of YAMAHA Musicsoft Downloader.
Therefore, in case of any security breach out SI can't warn you.
So what's now?
Firstly, update the virus definition of your anti-virus program and scan it again because some times old definitions show wrong scan results.
If it does not help you try some other antivirus program to scan the file like Avast! or Norton.
If doing all of this doesn't change the scan result than the only hope is to contact the Yamaha Support Team. Click HERE to go to the web site.