GPG.exe binary included

[Giampiero De Ciantis]

I have an inquiry about including a pre-built GPL binary within an  
application. The application contains a plugin that encrypts files  
using GPG.exe. The code in the plugin is not linked in any way other  
than to call GPG.exe command line with arguments to encrypt or decrypt  
a file. A notice in the application contains a GPL license attribution  
that states that source code is available for GPG.exe by request. Does  
the mere fact that the GPG.exe is included with the entire bundle  
automatically make the entire product fall under the GPL?