Testing an image directory for hidden rars?

How would someone go about quickly testing each and every image to see if it had a rar or any other file hidden inside of it? What language would be best for doing this, if a tool isn't already available?

Ok so I found the directory and I got the command line grep 'Rar!' *.jpg to go in with an error what is suppose to happen I thought it would find all the pictures with hidden files all it did was go to a new command line