Behavioral Characterization of Attacks on the Remote Desktop Protocol

The Remote Desktop Protocol (RDP) is popular for enabling remote access and administration of Windows systems; however, attackers can take advantage of RDP to cause harm to critical systems using it. Detection and classification of RDP attacks is a challenge because most RDP traffic is encrypted, and it is not always clear which connections to a system are malicious after manual decryption of RDP traffic. In this research, we used open-source tools to generate and analyze RDP attack data using a power-grid honeypot under our control. We developed methods for detecting and characterizing RDP attacks through malicious signatures, Windows event log entries, and network traffic metadata. Testing and evaluation of our characterization methods on actual attack data collected by four instances of our honeypot showed that we could effectively delineate benign and malicious RDP traffic and classify the severity of RDP attacks on unprotected or misconfigured Windows systems. The classification of attack patterns and severity levels can inform defenders of adversarial behavior in RDP attacks. Our results can also help protect national critical infrastructure, including Department of Defense systems.