Thursday, July 2, 2015

Hide any file inside an image file

This a small steganography hack that is fun and sometime really useful,  when  you want to send some file over internet, but upload of only image  file  are allowed on that server.
First here is the definition of stenography from Wikipedia. 
Steganography   (Listen) is the art and science of writing hidden messages in such a   way that no one, apart from the sender and intended recipient, suspects   the existence of the message, a form of security through obscurity.  The  word steganography is of Greek origin and means “concealed writing”  from  the Greek words steganos (στεγανός) meaning “covered or  protected”, and  graphei (γραφή) meaning “writing”.    

In  short, when you  see the file it's just a normal image, but it has some  hidden message  inside it, or in general it can contain anything, even a  whole movie.

There  are lots of tools available for this  purpose, but we can do it using  what we already have just the command  prompt in windows.
The requirement
  • The image file
  • The file to be hidden, the zip file
  • Command prompt
The image I will be using is this


and I want to hide a Ms word file and a Pdf behind this image, Select both the file and send to a Zip file.

Steps..
  1. Place the zip file and the image in a folder , I am placing it on the desktop.
  2. Open   cmd(command prompt) and then go to the directory where both the files   are. Like for example, in this case, it's "desktop". So you might need   to type cd desktop 
  3. Now type copy /b imagefilename + zipfilename [filename with extensions], here is the image for clarity.
  4. Now   the size of the image will increase, what this is doing is simple,  just  appending the second file to the first file and that /b is to  specify  that it is a binary file.
Opening The file
After   copying, the image file size will only increase, but it can be opened   normally and no difference will be seen except the size. To open the  Zip  file, open this image with any Zip tool like 7zip, winrar, or winzip and you can find all the files there, just extract it wherever you want.

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