The Mod Packer is a command line tool for packing a compiled dll file, modinfo.txt and any assets into an encrypted and simple to download and use mod package that is read by UMF.
This tool is located in uModFramework\Tools\UMF.ModPacker.exe and will only function within this folder while installed into a game.
It supports the following command line options:
-packmod “<Mod Name>” “<Path to folder containing mod files>” (<version>)

Note that the Project Generator already includes this command line tool into the build instructions, so you should normally not need to do anything with this.