Neural Steganalysis with Spatial Rich Models for Image Steganography Detection
Digital image steganalysis is the process of detecting if an image contains concealed data embedded within its pixel space inserted via a steganography algorithm. The detection of these images is highly motivated by Advanced Persistent Threat (APT) groups, such as APT37 Reaper, commonly utilizing these techniques to transmit malicious shellcode to perform further post-exploitation activity on a compromised host. Performing detection has become increasingly difficult due to modern steganography algorithms advancing at a greater rate than the steganalysis techniques designed to combat them. The task of detection is challenging due to modern steganography techniques that embed messages into images with only minor modifications to the original content which varies from image to image. In this paper, we pipeline Spatial Rich Models (SRM) feature extraction, Principal Component Analysis (PCA), and Deep Neural Networks (DNNs) to perform image steganalysis. Our proposed model, Neural Spatial Rich Models (NSRM) is an ensemble of DNN classifiers trained to detect 4 different state-of-the-art steganography algorithms at 5 different embedding rates, allowing for an end-to-end model which can be more easily deployed at scale. Additionally our results show our proposed model outperforms other current state-of-the-art neural network based image steganalysis techniques. Lastly, we provide an analysis of the current academic steganalysis benchmark dataset, BOSSBase, as well as performance of detection of steganography in various file formats with the hope of moving image steganalysis algorithms towards the point they can be utilized in actual industry applications.