Deep Dive into Insider Threats: Malicious Activity Detection within Enterprise

Haitao Xiao, Dan Du, Junrong Liu, Song Liu, Yan Zhu, Yuling Liu, Zhigang Lu

Abstract: With the digital transformation of enterprises, the increasing complexity of their internal information systems poses a growing challenge in terms of insider threats. Most existing research focuses on user-level and session-level insider threat detection, neglecting activity-level detection, leading to a lack of fine-grained insider threat detection. To tackle the aforementioned issue, we propose MADE, a novel method for detecting malicious activities within enterprise environments. MADE first encodes user multi-source activity logs into activity sequences and learns the semantic representations of activities within the sequences through embedding. Following this, we design an activity detection network based on Bidirectional Long Short-Term Memory (BiLSTM), Convolutional Neural Network (CNN), and Conditional Random Field (CRF). Combining adversarial training, our activity detection network learns the embedded activity sequences and identifies malicious activities. Extensive experimental results on the CERT R4.2 and R5.2 datasets demonstrate the effectiveness of our proposed MADE method.