Semi-supervised Deep Learning for Network Anomaly Detection

Deep learning promotes the fields of image processing, machine translation and natural language processing etc. It also can be used in network anomaly detection. In practice, it is not hard to obtain normal instances. However, it is always difficult to label anomalous instances. Semi-supervised learning can be utilized to resolve this problem. In this paper, we make a comprehensive study of semi-supervised deep learning techniques for network anomaly detection. Three kinds of deep learning techniques including GAN (Generative Adversarial networks), Auto-encoder and LSTM (Long Short-Term Memory) are studied on the latest network traffic dataset of CICIDS2017. Five deep architectures based on semi-supervised learning are designed, including BiGAN, regular GAN, WGAN, Auto-encoder and LSTM. Seven schemes of semi-supervised deep learning for anomaly detection are proposed according to different functions of anomaly score. Grid search is utilized to find the threshold of anomaly detection. Two traditional schemes of machine learning are also adopted to compare performance. There are altogether nine schemes of anomaly detection for CICIDS2017. From results of the experiment for network anomaly detection, it can be found that Auto-encoder outperforms LSTM and the three kinds of GAN. BiGAN and LSTM are both better than WGAN and regular GAN. All the seven schemes of semi-supervised deep learning for anomaly detection outperform the two traditional schemes. The work and results in this paper are meaningful on the application of semi-supervised deep learning for network anomaly detection.