Hiding a compressed file in an image

In fact, you only need one command. Run cmd to execute the command

Copy/B {image file name} + {compressed package file name} {output file name}

For example, I put all the images and compressed packages in a directory and then run the following command in the current directory:
Copy/B ustc.jpg + test.rar test.jpg

Save and change the extension to rar to see what the result is.

 

After verification, not only jpg and rar can be synthesized in this way, but also gif and bmp image formats and zip formats can be synthesized.