Stego Tricks
Some info was taken from https://0xrick.github.io/lists/stego/ and from https://github.com/DominicBreuker/stego-toolkit
Extracting data from all files
Binwalk
Binwalk is a tool for searching binary files, like images and audio files, for embedded hidden files and data.
It can be installed with apt, and the source can be found on Github.
Useful commands:
binwalk file : Displays the embedded data in the given file
binwalk -e file : Displays and extracts the data from the given file
binwalk --dd ".*" file : Displays and extracts the data from the given file
Foremost
Foremost is a program that recovers files based on their headers, footers, and internal data structures. I find it especially useful when dealing with png images. You can select the files that Foremost will extract by changing the config file in /etc/foremost.conf.
It can be installed with apt, and the source can be found on Github.
Useful commands:
foremost -i file : extracts data from the given file.
Exiftool
Sometimes, important stuff is hidden in the metadata of an image or file; exiftool can be very helpful to view file metadata.
You can get it from here
Useful commands:
exiftool file : shows the metadata of the given file
Exiv2
A tool similar to exiftool.
It can be installed with apt, and the source can be found on Github.
Official website
Useful commands:
exiv2 file : shows the metadata of the given file
File
Check out what kind of file you have
Strings
Extract strings from the file.
Useful commands:
strings -n 6 file: Extract the strings with min length of 6
strings -n 6 file | head -n 20: Extract first 20 strings with min length of 6
strings -n 6 file | tail -n 20: Extract last 20 strings with min length of 6
strings -e s -n 6 file: Extract 7bit strings
strings -e S -n 6 file: Extract 8bit strings
strings -e l -n 6 file: Extract 16bit strings (little-endian)
strings -e b -n 6 file: Extract 16bit strings (big-endian)
strings -e L -n 6 file: Extract 32bit strings (little-endian)
strings -e B -n 6 file: Extract 32bit strings (big-endian)
cmp - Comparison
If you have some modified image/audio/video, check if you can find the exact original one on the internet, then compare both files with:
Extracting hidden data in text
Hidden data in spaces
If you find that a text line is bigger than it should be, then some hidden information could be included inside the spaces using invisible characters. To extract the data, you can use: https://www.irongeek.com/i.php?page=security/unicode-steganography-homoglyph-encoder
Extracting data from images
identify
GraphicMagick tool to check what kind of image a file is. Also checks if the image is corrupted.
If the image is damaged, you may be able to restore it by simply adding a metadata comment to it (if it's very badly damaged this won't work):
Steghide [JPEG, BMP, WAV, AU]
Steghide is a steganography program that hides data in various kinds of image and audio files. It supports the following file formats : JPEG, BMP, WAV and AU. It’s also useful for extracting embedded and encrypted data from other files.
It can be installed with apt, and the source can be found on Github.
Useful commands:
steghide info file : displays info about whether a file has embedded data or not.
steghide extract -sf file [--passphrase password] : extracts embedded data from a file [using a password]
You can also extract content from steghide using the web: https://futureboy.us/stegano/decinput.html
Bruteforcing Steghide: stegcracker stegcracker <file> [<wordlist>]
Zsteg [PNG, BMP]
zsteg is a tool that can detect hidden data in png and bmp files.
To install it : gem install zsteg. The source can also be found on Github
Useful commands:
zsteg -a file : Runs every detection method on the given file
zsteg -E file : Extracts data with the given payload (example : zsteg -E b4,bgr,msb,xy name.png)
stegoVeritas JPG, PNG, GIF, TIFF, BMP
Capable of a wide variety of simple and advanced tricks, this tool can check file metadata, create transformed images, brute force LSB, and more. Check out stegoveritas.py -h to read about its full capabilities. Execute stegoveritas.py stego.jpg to run all checks.
Stegsolve
Sometimes there is a message or a text hidden in the image itself that, in order to view it, must have color filters applied, or some color levels changed. Although you can do that with something like GIMP or Photoshop, Stegsolve makes it easier. It's a small Java tool that applies many useful color filters on images; In CTF challenges, Stegsolve is often a real timesaver.
You can get it from Github
To use it, just open the image and click on the < > buttons.
FFT
To find hidden content using Fast Fourier T:
pip3 install opencv-python
Stegpy [PNG, BMP, GIF, WebP, WAV]
A program for encoding information in image and audio files through steganography. It can store the data as either plaintext or encrypted. Find it on Github.
Pngcheck
Get details on a PNG file (or even find out it's actually something else!).
apt-get install pngcheck: Install the tool
pngcheck stego.png : Obtain info about the PNG
Some other image tools worth mentioning
Extracting data from audios
ffmpeg
ffmpeg can be used to check the integrity of audio files, reporting various information about the file, as well as any errors it finds.
ffmpeg -v info -i stego.mp3 -f null -
Wavsteg [WAV]
WavSteg is a Python3 tool that can hide data, using least significant bit, in wav files. It can also search for, and extract, data from wav files.
You can get it from Github
Useful commands:
python3 WavSteg.py -r -b 1 -s soundfile -o outputfile : Extracts to an output file (taking only 1 lsb)
python3 WavSteg.py -r -b 2 -s soundfile -o outputfile : Extracts to an output file (taking only 2 lsb)
Deepsound
Hide, and check for, information encrypted with AES-265 in sound files. Download from the oficial page. To search for hidden info, simply run the program and open the sound file. If DeepSound finds any data hidden, you'll need to provide the password to unlock it.
Sonic visualizer
Sonic visualizer is a tool for viewing and analyzing the contents of audio files. It can be very helpful when facing audio steganography challenges; you can reveal hidden shapes in audio files that many other tools won't detect. If you're stuck, always check the spectrogram of the audio. Offical Website
DTMF Tones - Dial tones
Other tricks
Binary length SQRT - QR Code
If you receive binary data with an SQRT length of an entire number, it could be some kind of QR code:
To convert binary "1"s and "0"s to a proper image: https://www.dcode.fr/binary-image To read a QR code: https://online-barcode-reader.inliteresearch.com/
Braile
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