An Investigation into Steganalysis Techniques in Media File Forensics and the Use of Machine Learning in Identifying Affected Files

Description

Steganalyse.py is a Python tool that uses SVMs and Logistic Regression to classify image and video files as being either clean or steganographic.

The features that have been successfully utilised are:

Lyu and Farid's (2003, quoted in Schaathun, 2012a, p. 96; 2006, quoted in Schaathun, 2012a, p. 96) higher order statistics for image steganalysis, through the features package of the pysteg (Schaathun, 2012b) Python module.
Zhang, Cao and Zhao's (2017) features for video steganalysis based on "near perfect estimation for local optimality", through Zhang's (2019) NPELO extractor.

Requirements

Runs only on UNIX systems, due to dependence on subprocess module (tested on Ubuntu 18.04)
Videos must be a must be a raw H.264 bitstream for steganalysis
Python 3
Python 2.7
wine Python module (more info)
pysteg Python module (Schaathun, 2012b)
NPELO extractor (Zhang, 2019)
curl [if using get-training-images.sh]
pwgen [if using get-training-images.sh]
steghide [if using get-training-images.sh]

See requirements-p3.txt for required Python 3 modules, and requirements-p2.txt for required Python 2.7 modules.

Usage

Main program: steganalyse.py

Note that train-classifiers.py (and get-training-images.sh, if an image dataset is required) needs to be run first, and the .joblib classifiers should be in the same directory as steganalyse.py.

$ python3 ./steganalyse.py -h

usage: steganalyse.py [-h] [-f FILENAMES [FILENAMES ...]] [-t TEXT_FILE]

A program to detect image or video steganography

optional arguments:
  -h, --help            show this help message and exit
  -f FILENAMES [FILENAMES ...], --filenames FILENAMES [FILENAMES ...]
                        Name(s) of file(s) to analyse
  -t TEXT_FILE, --text-file TEXT_FILE
                        Get filenames from a list in a .txt file

Creating & training classifiers: train-classifiers.py

Training data should be segmented into folders as follows:

training-data/
- images/
  - clean/
  - stego/
- videos/
  - clean/
  - stego/

$ python3 ./train-classifiers.py -h

usage: train-classifiers.py [-h] dir_location

A script to extract image & video features, & train machine learning
classifiers [SVM & Logistic Regression].

positional arguments:
  dir_location  Directory location of training data in quotation marks

optional arguments:
  -h, --help    show this help message and exit

Gathering image files: get-training-images.sh

Input: .txt file list of image URLs.

$ ./get-training-images.sh url-list.txt

Due to availability of existing video datasets and video steganography tools, the video files must be gathered and prepared manually.

References

Schaathun, H. G. (2012a) Machine learning in image steganalysis, Chichester: Wiley.

Schaathun, H. G. (2012b) pysteg [Python library]. Available at: http://www.ifs.schaathun.net/pysteg/ (Accessed: 11 October 2018).

Zhang, H., Cao, Y. and Zhao, X. (2017) 'A steganalytic approach to detect motion vector modification using near-perfect estimation for local optimality', IEEE Transactions on Information Forensics and Security, 12(2), pp. 465-478. doi: 10.1109/TIFS.2016.2623587

Zhang, H. (2019) 'Feature extractors for video steganalysis', GitHub repository, GitHub. Available at: https://github.com/zhanghong863/Feature-Extractors-for-Video-Steganalysis (Accessed: 1 February 2019).

jessica0x73 / steganalyse