It's clearly a false positive, but Microsoft is ADAMENT that this .rmskin / .zip contains that script trojan. I think all you can do is start the process of disputing it:
https://www.microsoft.com/en-us/wdsi/filesubmission
https://www.microsoft.com/en-us/wdsi/filesubmission
Statistics: Posted by jsmorley — Today, 3:34 pm