gifshuffle software package provides Steganography program to gif images, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install gifshuffle
gifshuffle is installed in your system.
Make ensure the gifshuffle package were installed using the commands given below,
$ sudo dpkg-query -l | grep gifshuffle *
You will get with gifshuffle package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Miscellaneous |
| Package | gifshuffle |
| Version | 2.0-1 |
| Description | Steganography program to gif images |
| Sub Section | Miscellaneous |