Autoscopy Jr.: Intrusion Detection for Embedded Control Systems

Securing embedded control systems within the power grid presents a unique challenge: on top of the resource restrictions inherent to these devices, SCADA systems must also accommodate strict timing requirements that are non-negotiable, and their massive scale greatly amplifies costs such as power consumption. These constraints make the conventional approach to host intrusion detection--namely, employing virtualization in some manner--too costly or impractical for embedded control systems within critical infrastructure. Instead, we take an in-kernel approach to system protection, building upon the Autoscopy system developed by Ashwin Ramaswamy that places probes on indirectly-called functions and uses them to monitor its host system for behavior characteristic of control-flow-altering malware, such as rootkits. In this thesis, we attempt to show that such a method would indeed be a viable method of protecting embedded control systems. We first identify several issues with the original prototype, and present a new version of the program (dubbed Autoscopy Jr.) that uses trusted location lists to verify that control is coming from a known, trusted location inside our kernel. Although we encountered additional performance overhead when testing our new design, we developed a kernel profiler that allowed us to identify the probes responsible for this overhead and discard them, leaving us with a final probe list that generated less than 5% overhead on every one of our benchmark tests. Finally, we attempted to run Autoscopy Jr. on two specialized kernels (one with an optimized probing framework, and another with a hardening patch installed), finding that the former did not produce enough performance benefits to preclude using our profiler, and that the latter required a different method of scanning for indirect functions for Autoscopy Jr. to operate. We argue that Autoscopy Jr. is indeed a feasible intrusion detection system for embedded control systems, as it can adapt easily to a variety of system architectures and allows us to intelligently balance security and performance on these critical devices

Wide spectrum attribution: Using deception for attribution intelligence in cyber attacks

Modern cyber attacks have evolved considerably. The skill level required to conduct a cyber attack is low. Computing power is cheap, targets are diverse and plentiful. Point-and-click crimeware kits are widely circulated in the underground economy, while source code for sophisticated malware such as Stuxnet is available for all to download and repurpose. Despite decades of research into defensive techniques, such as firewalls, intrusion detection systems, anti-virus, code auditing, etc, the quantity of successful cyber attacks continues to increase, as does the number of vulnerabilities identified. Measures to identify perpetrators, known as attribution, have existed for as long as there have been cyber attacks. The most actively researched technical attribution techniques involve the marking and logging of network packets. These techniques are performed by network devices along the packet journey, which most often requires modification of existing router hardware and/or software, or the inclusion of additional devices. These modifications require wide-scale infrastructure changes that are not only complex and costly, but invoke legal, ethical and governance issues. The usefulness of these techniques is also often questioned, as attack actors use multiple stepping stones, often innocent systems that have been compromised, to mask the true source. As such, this thesis identifies that no publicly known previous work has been deployed on a wide-scale basis in the Internet infrastructure. This research investigates the use of an often overlooked tool for attribution: cyber de- ception. The main contribution of this work is a significant advancement in the field of deception and honeypots as technical attribution techniques. Specifically, the design and implementation of two novel honeypot approaches; i) Deception Inside Credential Engine (DICE), that uses policy and honeytokens to identify adversaries returning from different origins and ii) Adaptive Honeynet Framework (AHFW), an introspection and adaptive honeynet framework that uses actor-dependent triggers to modify the honeynet envi- ronment, to engage the adversary, increasing the quantity and diversity of interactions. The two approaches are based on a systematic review of the technical attribution litera- ture that was used to derive a set of requirements for honeypots as technical attribution techniques. Both approaches lead the way for further research in this field

Security hardened remote terminal units for SCADA networks.

Remote terminal units (RTUs) are perimeter supervisory control and data acquisition (SCADA) devices that measure and control actual physical devices. Cyber security was largely ignored in SCADA for many years, and the cyber security issues that now face SCADA and DCS, specifically RTU security, are investigated in this research. This dissertation presents a new role based access control model designed specifically for RTUs and process control. The model is developed around the process control specific data element called a point, and point operations. The model includes: assignment constraints that limit the RTU operations that a specific role can be assigned and activation constraints that allow a security administrator to specify conditions when specific RTU roles or RTU permissions cannot be used. RTU enforcement of the new access control model depends on, and is supported by, the protection provided by an RTU\u27s operating system. This dissertation investigates two approaches for using minimal kernels to reduce potential vulnerabilities in RTU protection enforcement and create a security hardened RTU capable of supporting the new RTU access control model. The first approach is to reduce a commercial OS kernel to only those components needed by the RTU, removing any known or unknown vulnerabilities contained in the eliminated code and significantly reducing the size of the kernel. The second approach proposes using a microkernel that supports partitioning as the basis for an RTU specific operating system which isolates network related RTU software, the RTU attack surface, from critical RTU operational software such as control algorithms and analog and digital input and output. In experimental analysis of a prototype hardened RTU connected to real SCADA hardware, a reduction of over 50% was obtained in reducing a 2.4 Linux kernel to run on actual RTU hardware. Functional testing demonstrated that different users were able to carryout assigned tasks with the limited set of permissions provided by the security hardened RTU and a series of simulated insider attacks were prevented by the RTU role based access control system. Analysis of communication times indicated response times would be acceptable for many SCADA and DCS application areas. Investigation of a partitioning microkernel for an RTU identified the L4 microkernel as an excellent candidate. Experimental evaluation of L4 on real hardware found the IPC overhead for simulated critical RTU operations protected by L4 partitioning to be sufficiently small to warrant continued investigation of the approach

Preliminary Specification of Services and Protocols

This document describes the preliminary specification of services and protocols for the Crutial Architecture. The Crutial Architecture definition, first addressed in Crutial Project Technical Report D4 (January 2007), intends to reply to a grand challenge of computer science and control engineering: how to achieve resilience of critical information infrastructures, in particular in the electrical sector. The definitions herein elaborate on the major architectural options and components established in the Preliminary Architecture Specification (D4), with special relevance to the Crutial middleware building blocks, and are based on the fault, synchrony and topological models defined in the same document. The document, in general lines, describes the Runtime Support Services and APIs, and the Middleware Services and APIs. Then, it delves into the protocols, describing: Runtime Support Protocols, and Middleware Services Protocols. The Runtime Support Services and APIs chapter features as a main component, the Proactive-Reactive Recovery Service, whose aim is to guarantee perpetual execution of any components it protects. The Middleware Services and APIs chapter describes our approach to intrusion-tolerant middleware. The middleware comprises several layers. The Multipoint Network layer is the lowest layer of CRUTIAL's middleware, and features an abstraction of basic communication services, such as provided by standard protocols, like IP, IPsec, UDP, TCP and SSL/TLS. The Communication Support Services feature two important building blocks: the Randomized Intrusion-Tolerant Services (RITAS), and the Overlay Protection Layer (OPL) against DoS attacks. The Activity Support Services currently defined comprise the CIS Protection service, and the Access Control and Authorization service. Protection as described in this report is implemented by mechanisms and protocols residing on a device called Crutial Information Switch (CIS). The Access Control and Authorization service is implemented through PolyOrBAC, which defines the rules for information exchange and collaboration between sub-modules of the architecture, corresponding in fact to different facilities of the CII's organizations.The Monitoring and Failure Detection layer contains a preliminary definition of the middleware services devoted to monitoring and failure detection activities. The remaining chapters describe the protocols implementing the above-mentioned services: Runtime Support Protocols, and Middleware Services Protocol

Improving cyber security in industrial control system environment.

Integrating industrial control system (ICS) with information technology (IT) and internet technologies has made industrial control system environments (ICSEs) more vulnerable to cyber-attacks. Increased connectivity has brought about increased security threats, vulnerabilities, and risks in both technology and people (human) constituents of the ICSE. Regardless of existing security solutions which are chiefly tailored towards technical dimensions, cyber-attacks on ICSEs continue to increase with a proportionate level of consequences and impacts. These consequences include system failures or breakdowns, likewise affecting the operations of dependent systems. Impacts often include; marring physical safety, triggering loss of lives, causing huge economic damages, and thwarting the vital missions of productions and businesses. This thesis addresses uncharted solution paths to the above challenges by investigating both technical and human-factor security evaluations to improve cyber security in the ICSE. An ICS testbed, scenario-based, and expert opinion approaches are used to demonstrate and validate cyber-attack feasibility scenarios. To improve security of ICSs, the research provides: (i) an adaptive operational security metrics generation (OSMG) framework for generating suitable security metrics for security evaluations in ICSEs, and a list of good security metrics methodology characteristics (scope-definitive, objective-oriented, reliable, simple, adaptable, and repeatable), (ii) a technical multi-attribute vulnerability (and impact) assessment (MAVCA) methodology that considers and combines dynamic metrics (temporal and environmental) attributes of vulnerabilities with the functional dependency relationship attributes of the vulnerability host components, to achieve a better representation of exploitation impacts on ICSE networks, (iii) a quantitative human-factor security (capability and vulnerability) evaluation model based on human-agent security knowledge and skills, used to identify the most vulnerable human elements, identify the least security aspects of the general workforce, and prioritise security enhancement efforts, and (iv) security risk reduction through critical impact point assessment (S2R-CIPA) process model that demonstrates the combination of technical and human-factor security evaluations to mitigate risks and achieve ICSE-wide security enhancements. The approaches or models of cyber-attack feasibility testing, adaptive security metrication, multi-attribute impact analysis, and workforce security capability evaluations can support security auditors, analysts, managers, and system owners of ICSs to create security strategies and improve cyber incidence response, and thus effectively reduce security risk.PhD in Manufacturin