hello, when you directly downloaded the setup file from mozilla.org, then the file will be clean and it's likely a false positive (all the other vendors did detect nothing suspicious). you can also download the full setup file and not just the small installer which downloads the main components during the setup from http://www.mozilla.org/firefox/all/

Hello Philipp, Thxs for the Reply.

FF Setup File --

 *  Have Downloaded from Mozilla.org only & no other source
 *  Yes, on Virustotal only McAfee-GW-Edition has raised a RED Flag. 
     Every other AV has cleared it clean.

FF Full Setup file --

 Downloaded from http://www.mozilla.org/firefox/all/ , is being shown All clean by Virustotal

Still, would be better if someone could take this forward exhaustively & find the technical reason for Setup file from Mozilla.org detecting "Heuristic.BehavesLike.Win32.Suspicious-PKR.G".

Report it to Virustotal your self, since you are a user of that program.

This looks like a false positive from mcafee (happens from time to time with various vendors), so please feel free to report to them as a false positive if you use their product.

The installer is safe to use so feel free to continue installing Firefox.