Top 5 Cyberattacks on Critical Infrastructure

Cyber attacks on critical infrastructure go far beyond stolen data. They disrupt hospitals, halt power and water systems, and paralyse transport networks people depend on daily.

Nation-state hackers, ransomware gangs, and hacktivist groups are increasingly targeting critical infrastructure sectors for political and financial gain. IBM reports that ransomware attacks on the healthcare sector have surged over 300% since 2015.

As attackers grow more advanced and brazen, defending these essential services and implementing critical infrastructure cybersecurity measures is now a global priority.

What is Critical National Infrastructure?

Critical infrastructure refers to the essential physical and digital systems that are crucial for a nation’s economy, security, and public health.

These sectors include:

• Energy (grids, pipelines)
• Water supply and wastewater
• Healthcare systems
• Transportation networks
• Telecom and communications
• Food and agriculture
• Finance and banking
• Government services
  

A lot of these sectors rely on older industrial control systems (ICS) and SCADA technologies, which were designed way before cybersecurity became a major concern. They are easier to break into and harder to protect now that they are digital and connected.

A single breach, such as taking down a fuel pipeline, can send shockwaves through multiple sectors, leading to national disruption. 

Recent Cyber Attacks on Critical Infrastructure

Some notable cyberattacks on critical infrastructure include the breach of the U.S. healthcare system in 2024, a simulated attack on the Netherlands' solar infrastructure in 2024, the Pennsylvania water system incident in 2023, the Ukraine power grid attack in 2022, and the Colonial Pipeline attack in 2021. 

1. USA Healthcare System – 2024

On February 21, 2024, the Russian-linked BlackCat/ALPHV group launched a ransomware attack on Change Healthcare, the largest healthcare payment clearinghouse in the United States. This attack brought operations to a standstill for nearly a month.

Change Healthcare handles over 14 billion transactions each year. The attack disrupted billing, prescription processing, and insurance workflows. Patients were turned away, surgeries faced delays, and providers had to revert to manual paperwork. Some clinics even had to cover costs out of their own pockets to keep services running.

The American Hospital Association labelled the incident as “the most significant and consequential cyberattack on the U.S. healthcare system.” The breach highlighted just how deeply the system relies on digital infrastructure. 

2. Netherlands Solar Infrastructure – 2024

In 2024, two ethical hackers from the Dutch Institute for Vulnerability Disclosure (DIVD) found six zero-day vulnerabilities in Enphase IQ Gateway solar controllers. These controllers manage over 4 million solar systems across 150 countries. Three vulnerabilities allowed full remote control of devices exposed to the public internet. Before they could exploit them, the hackers responsibly disclosed the flaws.

If malicious actors had exploited these flaws, they could have tampered with energy flow, triggered grid instability, or caused power outages.

The incident exposed the cybersecurity risks in solar energy systems and highlighted vulnerabilities in unmanaged IoT-connected devices. 

3. Pennsylvania Water System – 2023

In November 2023, a threat group called Cyber Av3ngers, linked to Iran, breached a Unitronics programmable logic controller (PLC) at the Municipal Water Authority of Aliquippa, Pennsylvania.

The compromised PLC controlled water pressure for a pump station serving over 7,000 residents. Attackers took control of the system as it was exposed to the internet and used default credentials. The system switched to manual operation, and fortunately, no water disruption occurred.

The breach highlighted the persistent SCADA vulnerabilities in local utility systems. After the attack, CISA, the FBI, and Israel’s CERT issued advisories to warn similar facilities. 

4. Ukraine Power Grid – 2022

In October 2022, Russia-linked APT group Sandworm launched a cyberattack on Ukraine’s energy grid. They used “living off the land” techniques, which rely on native tools instead of custom malware, to trip the circuit breakers at substations.

The attack caused power outages in four regions and coincided with physical missile strikes. Analysts believe the threat actors gained access as early as June 2022 and coordinated the cyberattack to maximise political damage.

This cyber threat to power grids was a clear example of cyber-physical warfare. Sandworm had previously launched similar attacks in Ukraine in 2015 and 2016. 

5. Colonial Pipeline – 2021

In May 2021, the DarkSide ransomware group attacked Colonial Pipeline, which transports 45% of the East Coast’s fuel supply. The attack forced the company to shut down operations for 11 days.

Colonial paid a $5 million ransom to regain access to its systems. The breach caused fuel shortages across 11,000 gas stations and led to panic buying. Fuel prices hit a six-year high.

Though the initial entry point remains unclear, the attack showed how IT-targeted ransomware can disrupt OT systems and critical national infrastructure. The incident led to federal investigations, emergency declarations, and regulatory changes. 

How Critical Infrastructure Is Vulnerable

Critical infrastructure is vulnerable due to outdated ICS and SCADA systems, weak IT-OT network segmentation, and insufficient monitoring.

Legacy ICS and SCADA Systems

These systems lack modern security controls and often do not include basic features like authentication or encryption. They lead to ICS cyberattacks and SCADA vulnerabilities.

Converged IT-OT Environments

Connecting OT systems to IT networks increases exposure. It allows attackers to use common enterprise vulnerabilities to pivot into critical infrastructure.

Insufficient Monitoring

Many infrastructure operators lack real-time monitoring and threat detection, giving attackers time to linger undetected. 

Top Threat Actors Targeting Infrastructure

Several cyber attackers target critical infrastructure, each with different goals and tactics. The top critical infrastructure cyberthreat actors include nation-state actors, cybercriminal gangs, hacktivists, and insider threats.

Nation-State Actors

Advanced Persistent Threat (APT) groups backed by governments often target rival nations. Examples include Russia’s Sandworm and Iran’s APT33.

Cybercriminal Gangs

Financially driven groups use ransomware on infrastructure to extort victims. Ransomware-as-a-Service (RaaS) platforms let less skilled criminals carry out major attacks.

Hacktivists and Insider Threats

Ideologically motivated hackers and disgruntled insiders, like unhappy employees, can sabotage systems or steal sensitive data. They often bypass traditional perimeter defences. 

Cybersecurity Measures for Critical Infrastructure

To defend critical infrastructure, organisations must implement cybersecurity measures such as zero trust and network segmentation. They must secure endpoints and enable real-time detection and response. These strategies bridge the IT-OT gap and reduce attacker dwell time.

Zero Trust Architecture (ZTA)

This model requires all users and devices to verify their identity, regardless of their network location.

Network Segmentation

Separating IT and OT networks limits the lateral movement of attackers within a compromised system.

Endpoint and OT Security

Industrial assets must use protection tools that understand ICS protocols and configurations.

Threat Detection and Incident Response

Operators should use tools that can help with real-time OT monitoring. They must also maintain a trained incident response team. 

Government Initiatives and Frameworks

Governments around the world are introducing stricter regulations and offering resources to protect critical infrastructure. They are introducing programs and frameworks like CISA advisories, the NIST CSF, and the EU’s NIS2 Directive to support infrastructure resilience.

U.S. CISA Programs

The Cybersecurity and Infrastructure Security Agency (CISA) offers advisories, assessments, and support for U.S. operators.

NIST Cybersecurity Framework (CSF)

The NIST CSF is a widely adopted framework that helps operators manage risk using the functions: Identify, Protect, Detect, Respond, and Recover.

EU NIS2 Directive

The European Union requires critical sectors to improve cyber hygiene, enforce incident reporting, and secure supply chains.

 

The Business and National Security Impacts

Cyberattacks on infrastructure create severe business and national consequences, from financial and reputational loss to geopolitical instability. Fuel shortages, delayed surgeries, and diplomatic fallouts are just a few examples of real-world impact.

Financial Losses

Organisations may suffer from ransom demands, legal fines, recovery costs, and downtime.

Reputational Harm

Public trust erodes when essential services like hospitals or gas stations fail due to cyberattacks.

Geopolitical Risks

Cyberattacks linked to foreign actors can heighten diplomatic tensions and even provoke military responses. 

Future Outlook and Emerging Trends

Organisations must evolve with the threat landscape by adopting new technologies and strategies.

AI and ML for ICS Security

Security teams are adopting AI to detect early-stage anomalies and reduce false positives in OT environments.

Cyber-Physical Convergence

Attackers are increasingly using digital methods to cause physical consequences, such as disabling machinery or sensors.

Increased OT Security Investment

Governments and private sector leaders are prioritising OT-focused security tools and advanced simulation training.