Pillar 4 – Critical Infrastructure & Real-World attacks

Cyberattacks are no longer confined to data theft or isolated systems—they now target the systems that keep society running. From energy grids and transport networks to financial systems and healthcare, critical infrastructure is a prime target for modern cyber threats.

This guide explores how real-world attacks happen, why critical systems are vulnerable, and what recent incidents reveal about the future of cyber risk.


What Is Critical Infrastructure?

Also known as known as CNI (Critical National Infrastructure), this includes systems essential to national security, economic stability, and public safety.

Key sectors:

  • Energy (power grids, oil, gas)
  • Water and utilities
  • Transport (air, rail, maritime)
  • Healthcare
  • Financial services
  • Telecommunications

Disruption in these sectors can have cascading, real-world consequences.


Why Critical Infrastructure Is Targeted

Attackers focus on these systems because:

  • Disruption has high impact and visibility
  • Organisations are more likely to pay ransoms
  • Legacy systems are harder to secure
  • Downtime can threaten safety and lives

Threat actors include:

  • Cybercriminal groups
  • Nation-state actors
  • Hacktivists

Common Attack Types

Ransomware Attacks

  • Encrypt critical systems
  • Disrupt operations
  • Force organisations into payment

These attacks increasingly target:

  • Hospitals
  • Local governments
  • Infrastructure operators

Network Intrusions

  • Exploiting exposed services
  • Gaining access via misconfigured systems
  • Moving laterally across networks

Supply Chain Attacks

  • Targeting third-party vendors
  • Compromising trusted software or hardware

Industrial & Operational Technology (OT) Attacks

  • Targeting ICS/SCADA systems
  • Disrupting physical processes

Real-World Cyber Attacks

Large-Scale Malware & Botnets

  • KadNap botnet
    • Compromised thousands of devices globally
    • Used for routing malicious traffic and maintaining persistence
  • Mirai botnet
    • One of the biggest botnet ever seen
    • Responsible for some of the biggest DDoS (by data volume) the Internet has seen

Demonstrates how large-scale infections support broader attack campaigns


Advanced Exploitation Campaigns

Highlights risks to mobile endpoints in critical environments


Access-Based Attacks

  • RDP exploitation
    • A major entry point into enterprise and infrastructure systems
    • Often used in ransomware campaigns
  • Reinforces the importance of secure remote access

Network-Level Attacks

Demonstrates risks in less controlled environments


Hardware & Signal Attacks


National Threat Perspective

Government assessments highlight the scale of the issue.

Insights from the National Crime Agency show:

  • Cybercrime is a top-tier national security threat
  • Ransomware remains one of the most disruptive attack types
  • Organised crime groups are increasingly sophisticated

Why These Attacks Are Increasing

Several trends are accelerating risk:

Digital Transformation

  • More connected systems
  • Expanded attack surfaces

Attack Automation

  • Exploit kits and botnets scale attacks
  • Lower barrier to entry for attackers
  • AI use in automated attacks

Interconnected Systems


Legacy Infrastructure

  • Outdated systems
  • Difficult to patch or replace

Defending Critical Infrastructure

Protecting critical systems requires a layered and specialised approach.


Zero Trust Security

  • Continuous verification
  • Strict access control

Network Segmentation

  • Separate IT and OT systems
  • Limit lateral movement

Monitoring & Detection

  • Real-time threat detection
  • Behavioural analysis

Incident Response Planning

  • Rapid containment strategies
  • Regular testing and drills

Identity & Access Management

  • Strong authentication (e.g., passkeys, MFA)
  • Privileged access controls

The Future of Critical Infrastructure Security

Expect:

  • Increased targeting by nation-state actors
  • Greater regulation and compliance requirements
  • Adoption of secure-by-design systems
  • Integration of AI for threat detection

The line between cyber and physical security will continue to blur.


Final Thoughts

Critical infrastructure is at the frontline of modern cyber conflict. Attacks are becoming more frequent, more sophisticated, and more impactful.

Understanding real-world attack techniques—and learning from actual incidents—is essential for building resilient systems.

This page serves as your foundation for exploring how cyber threats translate into real-world consequences.