ICS Study Guide 2026
Everything you need to pass the ICS exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 ICS Exam Format at a Glance
📚 ICS Topics to Study (63)
✍️ Sample ICS Questions & Answers
1. In ICS incident response, what does 'Defense in Depth' mean when applied to emergency procedures?
Defense in depth in emergency response means multiple overlapping response measures ensure that if one control fails, others still protect the system and people.
2. Which protocol is commonly used for communication in SCADA systems?
Modbus is one of the oldest and most widely used serial communication protocols in SCADA (Supervisory Control and Data Acquisition) systems and other industrial control applications. It allows devices like PLCs, RTUs, and sensors to communicate with each other and with supervisory systems. Despite its age, Modbus remains prevalent due to its simplicity and widespread adoption, though it lacks inherent security features.
3. Which NIST document provides a risk management framework (RMF) process applicable to federal ICS and OT systems?
NIST SP 800-37 defines the Risk Management Framework (RMF) — a six-step process (Prepare, Categorize, Select, Implement, Assess, Authorize, Monitor) applied to federal information systems including OT.
4. Why is regular security training important for all staff?
Regular security training reduces human error, the most common cause of security breaches, by keeping all staff aware of current threats and proper procedures.
5. During an ICS security assessment, auditors find that substation doors use padlocks from multiple vendors with varying key grades. What is the BEST remediation?
Standardizing to high-security, keyed-alike padlocks reduces key management complexity and ensures uniform resistance to picking and forced entry.
6. Why is staying current with industry developments important for Industrial Control Systems Security professionals?
Staying current ensures professionals provide the best possible service by incorporating the latest knowledge, techniques, and regulatory requirements.