Steganography

Online tools

Stegsolve.jar - Website
View the image in different colorspaces and alpha channels. I recommend using this patched version to be able to zoom out.
zsteg - GitHub
Command-line tool for PNG and BMP steganography.
jsteg - GitHub
Command-line tool for JPEG steganography.
Jstego
GUI tool for JPG steganography.
exiftool - Website
Tool to view and edit metadata in files.

Many steganography implementations exists. Here is a list of some of them.

steghide - Website
Hide data in various kinds of image- and audio-files using a passphrase. The password can be empty.
StegCracker - GitHub
Brute force passphrases for steghide encrypted files. Different data can have different passphrases.
StegSeek - GitHub
Faster than stegcracker.
steg_brute.py - GitHub
This is similar to stegcracker.
stepic - Website
Python library to hide data in images.
Digital Invisible Ink Tool - Website
A Java steganography tool that can hide any sort of file inside a digital image (regarding that the message will fit, and the image is 24 bit color)
ImageHide - Website
Hide any data in the LSB of an image. Can have a password.
stegoVeritas - GitHub
CLI tool to extract data from images.
Online LSB Tools
Some online tools to hide data in the LSB of images.
https://manytools.org/hacker-tools/steganography-encode-text-into-image/ Only supports PNG https://stylesuxx.github.io/steganography/
hipshot - Website
A python tool to hide a video in an image.

APNG
Animated PNG. Use apngdis to extract the frames and delays.
SVG Layers
Data can be hidden under SVG layers. inkview can be used to view and toggle the layers.
Image thumbnails
Image thumbnails can be different from the image itself.
```
exiftool -b -ThumbnailImage my_image.jpg > my_thumbnail.jpg
```
Corrupted image files
See Images files
- Images

Unicode Steganography / Zero-Width Space Characters
Messages can be hidden in the unicode characters. For example using the zero-width space character in it. Use a modern IDE like Code to find these characters.
Whitespace
Tabs and spaces (for example in the indentation) can hide data. Some tools can find it: snow or an esoteric programming language interpreter: https://tio.run/#whitespace
snow - Website
A command-line tool for whitespace steganography.

spectrogram - Wikipedia
An image can be hidden in the spectrogram of an audio file. audacity can show the spectrogram of an audio file. (To select Spectrogram view, click on the track name (or the black triangle) in the Track Control Panel which opens the Track Dropdown Menu, where the spectrogram view can be selected.. )
XIAO Steganography - Website
Windows software to hide data in audio.
DTMF - Wikipedia.
Dual tone multi-frequency is a signaling system using the voice-frequency band over telephone lines. It can be used to send text messages over the phone. Some tool: Detect DTMF Tones