Steghide is a program that is able to hide data in various kinds of image- and audio-files also known as the art of Steganography. The color- respectively sample-frequencies are not changed thus making the embedding resistant against first-order statistical tests.
We’ve created a text file with the name Secret.txt with some important contents in it, and we’re going to hide the text file inside a picture Logo.jpg, the command to do this is:
steghide embed -cf Logo.jpg -ef Secret.txt -p 123456
The “embed” is to tell the command to put inside the file Logo.jpg which is the cover file “-cf” a file named Secret.txt which is the embedded file “-ef” the “-p” is to set a password which in this case “123456”.
We can also embedded the file with a compression method if the file is little big with adding the parameter “-z”, he compression level vary from 1 to 9.
Also if you want to encrypt the file we are hiding we can specify encryption parameters. This option must be followed by one or two strings that identify an encryption algorithm or mode. You can get the names of all available algorithms and supported modes with the encinfo command. The default encryption is rijndael-128 (AES) in the cbc mode. If you do not want to use any encryption, use -e none.
The picture file looks normal even after we got the text file hidden inside it, using a tool like exiftool to view the information of the file won’t get much with it:
Let’s take a look on the file “Logo.jpg” information by running steghide –info Logo.jpg :
Now the file got some information so the prompt will ask for the passphrase and then show us that the file Logo.jpg got another file which is Secret.txt inside it, now let’s extract the file Secret.txt:
stighide extract –sf Logo.jpg