sudofry Open a terminal and navigate to the directory that contains your image and the zip file you want to hide inside of it. Replace the file names below with your own file names.
The cat command will read both files together and combine them into a new image file. The size of the new image file will be larger than the original image because it also contains the zip file inside, but you will not be able to visibly detect that it is there.
Now you can run the following command to unzip the file from the image. This does not remove the zip file from the image. It just extracts it. You can extract the zip file from this image an infinite number of times.
If you re-save the image, it will remove the zip file permanently.
