What you will need

First check all these boxes

  • Installed Steghide

  • have a picture or some file you want to embed data into

  • have another secret-message.txt file you want to embed

  • all files within the same directory

Now on your machine run this command

Shell
steghide --embed -p MyPassword -ef secret-message.txt -cf OriginalPicture.jpg -sf SecretDataPictureEndResultFileName.jpg

Now lets run through what that does, if you care.

Steghide - This is the binary you are running

--embed - This is saying I want to put data in not take data out

-p - use a password, anything after this becomes a password, uses standard UNIX so you can do stuff like " " or | | as surrounding to make a more complex password possible

-ef - this is the file you want to jam into the other file

-cf - This is the original picture you already had before running the command

-sf - This is a file that does not exist yet, but you can specify the output file with this flag

how to decode the message

Now to move on to the next part I like to use a tool like LocalSend to send the newly made SecretDataPictureEndResultFileName.jpg to another machine, then on the other machine you would run this command

Shell
steghide --extract -p MyPassowrd -sf SecretDataPictureEndResultFileName.jpg

Now lets run through what that does:

Steghide - This is the binary you are running

--extract - This is the opposite of what we did before, this time we decode not encode

-p - The same password we set from before

-sf - the file you know has secret data in