Cybersecurity risk assessment is an essential process for identifying and evaluating potential vulnerabilities and threats to these systems. There are several techniques to conduct cybersecurity assessments for Industrial Control Systems (ICS). Two common approaches are gap-based and risk-based analysis:
1. Gap-based analysis: This technique involves comparing the current state of cybersecurity in an OT/ICS system to a desired state or a set of established security standards or best practices, such as NIST or ISA/IEC 62443. The goal of the analysis is to identify gaps or discrepancies between the current and desired states, which can be addressed through the implementation of additional security controls or modifications to existing controls. The gap-based analysis provides a clear roadmap for improving the cybersecurity posture of the OT/ICS system and helps to prioritize and focus efforts and resources.
2. Risk-based analysis: This technique involves identifying potential cyber threats and assessing the likelihood and impact of those threats on the OT/ICS system. This analysis helps to prioritize cybersecurity efforts by focusing on the risks that pose the greatest threat to the system.
Both gap-based and risk-based analysis approaches are valuable for improving cybersecurity in OT/ICS systems. The gap-based analysis focuses on compliance with established cybersecurity standards, while risk-based analysis, such as Cyber PHA, focuses on identifying and mitigating specific risks.
What is Cyber PHA?
Cyber PHA (Process Hazard Analysis) is a methodology used to assess and manage cybersecurity risks in industrial control systems (ICS) and other critical infrastructures. PHA is a widely used risk assessment methodology in the process industries, such as petrochemicals and oil and gas, to identify and mitigate hazards that could cause damage to equipment, personnel, or the environment.
The Cyber PHA approach expands the traditional PHA methodology to include cybersecurity risks that could impact the availability, integrity, or confidentiality of process control systems. It involves identifying potential cyber threats and analyzing the potential consequences of those threats to the system, such as disruption of operations, physical damage to equipment, or the release of hazardous materials. By identifying and mitigating potential cyber threats, organizations can reduce the likelihood and impact of cyber incidents and protect the safety, security, and reliability of their operations.
How Cyber PHA is related to IEC 62443 standards?
Cyber PHA is one of the techniques recommended by the IEC 62443 standards for conducting cybersecurity risk assessments of IACS. The IEC 62443-3-2 standard specifies the requirements and provides guidance for conducting a cybersecurity risk assessment of an IACS, including the use of techniques such as Cyber PHA to identify and assess cybersecurity risks to the IACS.
The Cyber PHA technique is specifically referenced in the IEC 62443-3-2 standard as a method for identifying cybersecurity threats and their potential impact on the safety, reliability, and availability of the IACS. The standard provides guidance on the Cyber PHA process, including the definition of system boundaries, identification of potential cyber threats, identification of potential consequences, determination of risk, and development of mitigation strategies.
How Cyber PHA assessment can be done in IEC-62443-3-2?
The IEC 62443-3-2 standard provides guidance on conducting a cybersecurity risk assessment of an Industrial Automation and Control System (IACS), including the use of Cyber PHA (Process Hazard Analysis) to identify and assess cybersecurity risks to the IACS. In reference to the figure below from IEC-62443-3-2, Cyber PHA will be done at ZCR-1 and ZCR-5 blocks.
Here are the steps for conducting a Cyber PHA assessment under the IEC 62443-3-2 standard:
1. Define the scope and boundaries of the assessment: This involves identifying the IACS components that will be included in the assessment, as well as any external systems or networks that interact with the IACS.
2. Identify the assets and functions of the IACS: This involves identifying the hardware, software, data, and personnel that are involved in the operation and maintenance of the IACS.
3. Identify the potential cyber threats to the IACS: This involves identifying the potential sources, motivations, and methods of cyber attacks on the IACS.
4. Identify the potential consequences of a cyber attack on the IACS: This involves identifying the potential impacts of a cyber attack on the safety, reliability, and availability of the IACS.
5. Determine the likelihood and potential impact of the identified cyber threats: This involves assessing the likelihood of a cyber attack occurring and the potential impact on the IACS in terms of safety, reliability, and availability.
6. Determine the risk level and prioritize mitigation strategies: This involves using the Cyber PHA assessment results to determine the overall risk level to the IACS and prioritize the development of mitigation strategies.
7. Develop and implement mitigation strategies: This involves developing and implementing strategies to reduce the risk of cyber attacks and their potential impacts on the IACS.
8. Monitor and update the Cyber PHA assessment: This involves regularly monitoring the effectiveness of the mitigation strategies and updating the Cyber PHA assessment as needed to ensure ongoing cybersecurity risk management.
Cyber PHA Risk Assessment in More Details
Here is an example of how Cyber PHA can be conducted for an Industrial Automation and Control System (IACS) using the IEC 62443-3-2 standard:
1. Define the scope and boundaries of the assessment
In this example, the scope of the assessment is limited to a specific IACS that controls a critical infrastructure system. The assessment will include all components of the IACS, including hardware, software, data, and personnel.
2. Identify the assets and functions of the IACS
The second step is to identify the assets and functions of the IACS. This includes hardware, software, data, and personnel. The IACS consists of several interconnected components, including PLCs, HMIs, and a SCADA system. These components work together to control and monitor the critical infrastructure system.
3. Identify the potential cyber threats to the IACS
Potential cyber threats to the IACS include external attacks by malicious actors, internal attacks by employees or contractors, and accidental or unintentional actions by authorized personnel. These threats could result in unauthorized access to the IACS, data theft or destruction, or disruption of the critical infrastructure system. Threat sources should be identified, and their motives and capabilities should be analyzed.
4. Identify the potential consequences of a cyberattack on the IACS
The fourth step is to identify the potential consequences of a cyberattack on the IACS. This includes the impact of the cyberattack on the critical infrastructure system, including equipment failure, production delays, and safety hazards. The consequences should be analyzed in terms of their severity, duration, and potential secondary effects.
5. Determine the likelihood and potential impact of the identified cyber threats
The fifth step is to determine the likelihood and potential impact of the identified cyber threats. This includes analyzing historical data, industry trends, and expert judgment to determine the likelihood of occurrence and the potential impact of each cyber threat. The likelihood and potential impact can be assessed on a scale, such as high, medium, or low.
6. Determine the risk level and prioritize mitigation strategies
The sixth step is to determine the risk level of the IACS and prioritize mitigation strategies. The risk level should be based on the likelihood and potential impact of the identified cyber threats, and the consequences of a successful cyberattack on the critical infrastructure system. Mitigation strategies should be developed and prioritized based on the risk level. This includes identifying the most critical assets and functions, and determining the most effective mitigation strategies to reduce the risk of cyberattacks.
7. Develop and implement mitigation strategies
The mitigation strategies are developed and implemented using best practices and standards, including the IEC 62443 series of standards. The mitigation strategies are tested and verified to ensure that they effectively reduce the risk of cyberattacks on the IACS. Mitigation strategies are developed and prioritized based on the risk level, including improving access controls, implementing network segmentation, and providing cybersecurity training to personnel.
8. Monitor and update the Cyber PHA assessment
The final step is to monitor and update the Cyber PHA assessment. This includes monitoring the effectiveness of the mitigation strategies, and updating them as needed to maintain an effective cybersecurity posture. The Cyber PHA assessment should be updated regularly to reflect changes in the IACS, the threat landscape, or the critical infrastructure system.
Conduct Security Risk Assessment with Novesh
Conducting IEC 62443-3-2 using the Cyber PHA framework can significantly help your organization to reduce cyberattack risks. However, the process is complex and can be daunting without professional help.
On that note, Novesh offers the best OT cybersecurity services, including ICS risk assessment, using top-notch technology to ensure you never have to worry about your business data confidentiality and breaches. To better safeguard your industrial control system, reach out to our professionals to perform IEC 62443-3-2 risk assessment.
Contact us to join hands with the world-leading cybersecurity service providers to protect assets from cyber threats and safeguard your business data.