Rar/Zip file within JPEG image

I’m sure others may know this trick already:
This could be useful for sending encrypted information such as word documents, pdf files, programs, etc.
Take a normal JPEG file of your choice and a folder or file compressed in a zip or rar file.

Enter the command Prompt then type the following:

copy /b <image> + <compressed file> <outputfile>

Then you should receive a message that 1 file was copied.

If you can open the file as an image and open the archive(compressed) file in winrar, you have an embedded rar file.