Biblio

with the continuous growing threat of cyber terrorism, the vulnerability of the industrial control systems (ICS) is the most common subject for security researchers now. Attacks on ICS systems keep increasing and their impact leads to human safety issues, equipment damage, system down, unusual output, loss of visibility and control, and various other catastrophic failures. Many of the industrial control systems are relatively insecure with chronic and pervasive vulnerabilities. Modbus-Tcpis one of the widely used communication protocols in the ICS/ Supervisory control and data acquisition (SCADA) system to transmit signals from instrumentation and control devices to the main controller of the control center. Modbus is a plain text protocol without any built-in security mechanisms, and Modbus is a standard communication protocol, widely used in critical infrastructure applications such as power systems, water, oil & gas, etc.. This paper proposes a passive security solution called Deep-security-scanner (DSS) tailored to Modbus-Tcpcommunication based Industrial control system (ICS). DSS solution detects attacks on Modbus-TcpIcs networks in a passive manner without disturbing the availability requirements of the system.

The Domain Name System (DNS) is widely seen as a vital protocol of the modern Internet. For example, popular services like load balancers and Content Delivery Networks heavily rely on DNS. Because of its important role, DNS is also a desirable target for malicious activities such as spamming, phishing, and botnets. To protect networks against these attacks, a number of DNS-based security approaches have been proposed. The key insight of our study is to measure the effectiveness of security approaches that rely on DNS in large-scale networks. For this purpose, we answer the following questions, How often is DNS used? Are most of the Internet flows established after contacting DNS? In this study, we collected data from the University of Auckland campus network with more than 33,000 Internet users and processed it to find out how DNS is being used. Moreover, we studied the flows that were established with and without contacting DNS. Our results show that less than 5 percent of the observed flows use DNS. Therefore, we argue that those security approaches that solely depend on DNS are not sufficient to protect large-scale networks.