Stealthy Deception Attacks Against SCADA Systems

SCADA protocols for Industrial Control Systems (ICS) are vulnerable to network attacks such as session hijacking. Hence, research focuses on network anomaly detection based on meta--data (message sizes, timing, command sequence), or on the state values of the physical process. In this work we present a class of semantic network-based attacks against SCADA systems that are undetectable by the above mentioned anomaly detection. After hijacking the communication channels between the Human Machine Interface (HMI) and Programmable Logic Controllers (PLCs), our attacks cause the HMI to present a fake view of the industrial process, deceiving the human operator into taking manual actions. Our most advanced attack also manipulates the messages generated by the operator's actions, reversing their semantic meaning while causing the HMI to present a view that is consistent with the attempted human actions. The attacks are totaly stealthy because the message sizes and timing, the command sequences, and the data values of the ICS's state all remain legitimate. We implemented and tested several attack scenarios in the test lab of our local electric company, against a real HMI and real PLCs, separated by a commercial-grade firewall. We developed a real-time security assessment tool, that can simultaneously manipulate the communication to multiple PLCs and cause the HMI to display a coherent system--wide fake view. Our tool is configured with message-manipulating rules written in an ICS Attack Markup Language (IAML) we designed, which may be of independent interest. Our semantic attacks all successfully fooled the operator and brought the system to states of blackout and possible equipment damage

Assessing and augmenting SCADA cyber security: a survey of techniques

SCADA systems monitor and control critical infrastructures of national importance such as power generation and distribution, water supply, transportation networks, and manufacturing facilities. The pervasiveness, miniaturisations and declining costs of internet connectivity have transformed these systems from strictly isolated to highly interconnected networks. The connectivity provides immense benefits such as reliability, scalability and remote connectivity, but at the same time exposes an otherwise isolated and secure system, to global cyber security threats. This inevitable transformation to highly connected systems thus necessitates effective security safeguards to be in place as any compromise or downtime of SCADA systems can have severe economic, safety and security ramifications. One way to ensure vital asset protection is to adopt a viewpoint similar to an attacker to determine weaknesses and loopholes in defences. Such mind sets help to identify and fix potential breaches before their exploitation. This paper surveys tools and techniques to uncover SCADA system vulnerabilities. A comprehensive review of the selected approaches is provided along with their applicability

On Ladder Logic Bombs in Industrial Control Systems

In industrial control systems, devices such as Programmable Logic Controllers (PLCs) are commonly used to directly interact with sensors and actuators, and perform local automatic control. PLCs run software on two different layers: a) firmware (i.e. the OS) and b) control logic (processing sensor readings to determine control actions). In this work, we discuss ladder logic bombs, i.e. malware written in ladder logic (or one of the other IEC 61131-3-compatible languages). Such malware would be inserted by an attacker into existing control logic on a PLC, and either persistently change the behavior, or wait for specific trigger signals to activate malicious behaviour. For example, the LLB could replace legitimate sensor readings with manipulated values. We see the concept of LLBs as a generalization of attacks such as the Stuxnet attack. We introduce LLBs on an abstract level, and then demonstrate several designs based on real PLC devices in our lab. In particular, we also focus on stealthy LLBs, i.e. LLBs that are hard to detect by human operators manually validating the program running in PLCs. In addition to introducing vulnerabilities on the logic layer, we also discuss countermeasures and we propose two detection techniques.Comment: 11 pages, 14 figures, 2 tables, 1 algorith

On specification-based cyber-attack detection in smart grids

The transformation of power grids into intelligent cyber-physical systems brings numerous benefits, but also significantly increases the surface for cyber-attacks, demanding appropriate countermeasures. However, the development, validation, and testing of data-driven countermeasures against cyber-attacks, such as machine learning-based detection approaches, lack important data from real-world cyber incidents. Unlike attack data from real-world cyber incidents, infrastructure knowledge and standards are accessible through expert and domain knowledge. Our proposed approach uses domain knowledge to define the behavior of a smart grid under non-attack conditions and detect attack patterns and anomalies. Using a graph-based specification formalism, we combine cross-domain knowledge that enables the generation of whitelisting rules not only for statically defined protocol fields but also for communication flows and technical operation boundaries. Finally, we evaluate our specification-based intrusion detection system against various attack scenarios and assess detection quality and performance. In particular, we investigate a data manipulation attack in a future-orientated use case of an IEC 60870-based SCADA system that controls distributed energy resources in the distribution grid. Our approach can detect severe data manipulation attacks with high accuracy in a timely and reliable manner

A log mining approach for process monitoring in SCADA

SCADA (Supervisory Control and Data Acquisition) systems are used for controlling and monitoring industrial processes. We propose a methodology to systematically identify potential process-related threats in SCADA. Process-related threats take place when an attacker gains user access rights and performs actions, which look legitimate, but which are intended to disrupt the SCADA process. To detect such threats, we propose a semi-automated approach of log processing. We conduct experiments on a real-life water treatment facility. A preliminary case study suggests that our approach is effective in detecting anomalous events that might alter the regular process workflow

Adapting Bro into SCADA: Building Specification-based Intrusion Detection System for DNP3 Protocol

Modern SCADA systems are increasingly adopting Internet technology to control industry processes. With their security vulnerabilities exposed to public networks, an attacker is able to penetrate into these control systems to put remote facilities in danger. To detect such attacks, SCADA systems require an intrusion detection technique that can monitor network traffic based on proprietary network protocols. To achieve this goal, we adapt Bro, a network traffic analyzer widely used for intrusion detection, for use with SCADA systems. A built-in parser in Bro supports DNP3, a network protocol that is widely used in SCADA systems for electrical power grids. By exploiting Bro’s intrusion detection features, we apply a specification-based technique to analyze the parsed traffic. This built-in parser provides high visibility of network events in SCADA systems. Instead of exploiting an attack signature or a statistical normal pattern, SCADA-specific semantics related to each event are analyzed. Such analyses are made in terms of defined security policies which can be included at runtime. Our experiments are carried out in a laboratory-scale SCADA system environment with well-formatted but malicious network traffic. The detection capability and performance of the Bro-adapted intrusion detection system revealed in experiments show its potential applicability in the real SCADA system environment.Department of Energy & Department of Homeland Security/DE-OE0000097Ope

Smart Grid Technologies in Europe: An Overview

The old electricity network infrastructure has proven to be inadequate, with respect to modern challenges such as alternative energy sources, electricity demand and energy saving policies. Moreover, Information and Communication Technologies (ICT) seem to have reached an adequate level of reliability and flexibility in order to support a new concept of electricity network—the smart grid. In this work, we will analyse the state-of-the-art of smart grids, in their technical, management, security, and optimization aspects. We will also provide a brief overview of the regulatory aspects involved in the development of a smart grid, mainly from the viewpoint of the European Unio

Using a Specification-based Intrusion Detection System to Extend the DNP3 Protocol with Security Functionalities

Modern SCADA systems are increasingly adopting Internet technologies to control distributed industrial assets. As proprietary communication protocols are increasingly being used over public networks without efficient protection mechanisms, it is increasingly easier for attackers to penetrate into the communication networks of companies that operate electrical power grids, water plants, and other critical infrastructure systems. To provide protection against such attacks without changing legacy configurations, SCADA systems require an intrusion detection technique that can understand information carried by network traffic based on proprietary SCADA protocols. To achieve that goal, we adapted Bro, a specification-based intrusion detection system, for SCADA protocols in our previous work. In that work, we built into Bro a new parser to support DNP3, a complex proprietary network protocol that is widely used in SCADA systems for electrical power grids. The built-in parser provides clear visibility of network events related to SCADA systems. The semantics associated with the events provide us with a fine-grained operational context of the SCADA system, including types of operations and their parameters. Based on such information, we propose in this work two security policies to perform authentication and integrity checking on observed SCADA network traffic. To evaluate the proposed security policies, we simulated SCADA-specific attack scenarios in a test-bed, including real proprietary devices used in an electrical power grid. Experiments showed that the proposed intrusion detection system with the security policies can work efficiently in a large industry control environment that can include approximately 4000 devices.U.S. Department of Energy / DE-OE0000097National Science Foundation / OCI-1032889Infosys LimitedThe Boeing CompanyOpe