In my previous tutorial, I covered concealing messages in text files. Now, I'm going to show you how to conceal a text file in an image file using steghide, since SNOW only allows to store data in ASCII files. Like SNOW, steghide is a command-line program (I believe there is a GUI version available).
Steghide's official website states the following:
Steghide is a steganography program that is able to hide data in various kinds of image- and audio-files. The color- respectivly sample-frequencies are not changed thus making the embedding resistant against first-order statistical tests.
It's worth noting that this program is a bit more complex than SNOW, so I will only be covering the essential options. So without further ado, let's get started!
Just like SNOW, steghide's repositories are already present in Kali, so to install simply type
sudo apt-get install steghide
Concealing text files in image files
Like I said earlier, i'll cover the essential options of the program, so if you want the full list of options just type in the terminal:
The main options we'll take a look at are:
embed - embed data
extract - extract data
-ef - file to be embedded
-cf - cover-file (image/audio file)
-sf - stego-file
-xf - write the extracted data to <filename>
Let's imagine I want to share a secret file named "wordlist" and conceal it in an image file called "Robin.JPG" (To my understanding, only .jpg files work). I'd type:
steghide embed -ef wordlist -cf Robin.JPG
Now the program will ask you to setup a passphrase (just type whatever you want).
Retreiving the concealed file
To retrieve the hidden file, we type:
steghide extract -sf Robin.JPG -xf <some_file_name>
It'll ask you again for the passphrase. Now all you need to do is find the file with the extracted data and you're good to go!
That's it for this tutorial, hope you enjoyed reading as much as I did writing it!