Hiding files inside images

I remember back before data was a big thing on phones I used to put hidden files inside jpg images then send them to a friend with image text messages. Maybe not the most efficient way to send files but it was a fun little hack. Since that time we got e-mail and internet on our phones and I had forgotten all about this trick until I was reading some security stuff at work that talked about hiding malware inside files.

This kind of jogged my memory so I wanted to see if I could still hide files inside images today.

How to put hidden files inside of an image.

All you need is an image and a zip file with your hidden files inside it. I always use a zip file. I am guessing you could use any file type but I am not 100% sure how you would get other file types out easily.

Just open a windows command prompt and type ‘Copy /b”. the “/b” tells the computer to do a binary copy.

After that add the path to the original image and the path to the file you want to embed. Put a plus sign between them.

Then you type out the name of the new file. The whole command looks like this.

Copy /b image.jpg+file.zip newimage.jpg

Getting the file out of the image.

Now the built in windows zip tool will not notice that the image is also a zip file but if you have a program like 7-Zip then you can open the image with it and see what is inside.

Hidden files in text messages?

Now we have a hidden file inside of our image. But I wonder if I could still text it like I did in the old days?

So I uploaded the image to my Nexus 5X that uses the Project Fi network and I texted the image to my work phone that is a Google Pixel 2 on the Verizon network. Then I plugged up that work phone to my computer and pulled the image off. I opened the image with 7-Zip and the file was there! Then I opened the file to be sure it was not corrupted or anything and it worked fine!

Of course, my embedded file is small. There may be issues if the size got bigger. But I think that it is kind of cool that this still works.

Useful?

I have no clue how useful this would be but it is kind of neat. It is also cool that you can text these hidden files. I wonder what else would except these kinds of images and keep the secret files intact?