Top Critical Infrastructure Threats in 2025

As digital technologies and physical infrastructure grow more interconnected, critical infrastructure sectors such as energy, healthcare, and transportation face heightened cybersecurity risks. These essential services have become attractive targets for sophisticated threat actors who want to disrupt national stability.

The blend of legacy operational systems, rapid IoT adoption, and rising geopolitical tensions has created a rapidly changing threat landscape for critical infrastructure that demands constant attention.

What is Critical National Infrastructure?

Critical infrastructure refers to the systems, assets, and networks that are essential to a nation's security, economic stability, and public well-being.
The main types of critical infrastructure sectors are:

• Energy – Power generation, transmission, and fuel supply systems
• Water – Treatment plants, wastewater systems, and distribution networks
• Healthcare – Hospitals, emergency services, and pharmaceutical supply chains
• Transportation – Railways, airports, seaports, and traffic control systems
• Manufacturing – Industrial facilities that support national supply chains and defence
• Communications – Telecom networks, satellites, and internet infrastructure
• Finance – Banks, payment systems, and market infrastructure
• Government Services – Defence, law enforcement, and emergency responseFood and Agriculture – Production, processing, and distribution systems
  

Unlike traditional IT environments, these sectors rely heavily on industrial control systems (ICS) and supervisory control and data acquisition (SCADA) platforms. Such technologies often prioritise uptime and safety over cybersecurity. This makes them prone to both cyber and physical attacks and introduces serious SCADA vulnerabilities and ICS security risks that attackers can exploit.

Because these systems are so essential, even a short disruption can cause major problems like power cuts, unsafe water, delayed emergency services, or economic disruption. This makes critical infrastructure a high-value target for nation-state actors, cybercriminal groups, and hacktivists seeking to cause maximum harm or gain financially.

Top Critical Infrastructure Threats in 2025

The top critical infrastructure threats include ransomware targeting ICS/SCADA systems, nation-state cyber espionage campaigns, insider threats, vulnerable IoT/IIoT devices, hybrid physical-cyber attacks, supply chain attacks, legacy system exploits, and AI-driven attacks.

Ransomware Attacks on OT Systems

Ransomware attacks on critical infrastructure have come a long way from being merely tools for data theft. They are now being used to cause large-scale disruptions.

Modern ransomware strains now target ICS and SCADA systems directly. They focus on components like programmable logic controllers (PLCs) and human-machine interfaces (HMIs) to shut down OT systems entirely. Operational technology threats affect industrial sectors a great deal.  

The 2021 Colonial Pipeline attack and the 2022 ransomware breach of Costa Rica’s healthcare system reveal the true severity of modern infrastructure attacks. These events led to fuel shortages, service outages, and nationwide instability. Indeed, they went far beyond IT disruption, affecting public safety, halting critical services, and threatening national safety. 

Ransomware groups today often use double extortion tactics. This means they encrypt systems and also threaten to leak sensitive data. These groups are taking advantage of ICS-specific vulnerabilities more than ever.

Nation-State Cyber Espionage

Nation-state cyber espionage is escalating in 2025. Advanced Persistent Threat (APT) groups are actively targeting critical infrastructure sectors.

Sandworm is infamous for disrupting Ukraine’s power grid through sophisticated ICS-targeted malware.

APT33, an Iranian-backed group, has repeatedly targeted energy firms across the Middle East.

Volt Typhoon, a China-linked threat actor, has been linked to recent stealthy cyber intrusions into U.S. critical infrastructure networks.

These campaigns often focus on disrupting energy systems, revealing the growing risk of energy grid cyber attacks. Their goals range from surveillance and data theft to disruption and sabotage. These state-sponsored actors conduct stealthy, long-term campaigns designed to evade detection. Tactics include spear-phishing, zero-day exploits, and supply chain compromises.  

Insider Threats

Insider threats remain a serious risk, with both malicious insiders and negligent employees capable of causing harm. Insiders can introduce malware, disable controls, or leak sensitive data intentionally or accidentally.

The danger lies in the fact that they have access and can be invisible. Engineers and contractors often have elevated privileges, and their activity may blend in with their normal operations. Traditional detection tools like firewalls and SIEMs struggle to flag such threats.

Organisations without role-based access control (RBAC) or user behaviour analytics (UBA) are especially vulnerable. Improving identity governance and internal monitoring helps mitigate this risk. 

IoT and IIoT Vulnerabilities

Infrastructure systems rely on connected devices like smart meters, industrial sensors, and telemetry units. However, many Internet of Things (IoT) and Industrial IoT (IIoT) devices still use outdated protocols like Modbus, MQTT, and BACnet, with default passwords and little security in place.

These devices often run 24/7 in remote or hard-to-reach environments. They do not go through standard patching and monitoring cycles. Attackers can easily exploit them to break into sensitive systems or disrupt operations.

Compromised IoT gateways often serve as initial access points for broader ICS-targeted attacks. 

Physical Attacks with Cyber Motives

Hybrid attacks that combine physical sabotage with cyber intrusions are on the rise.

The 2022 substation attack in North Carolina paired physical damage with system-level interference to prolong outages.

These dual-vector attacks overwhelm defences and delay recovery.  

State-backed and ideological attackers are increasingly using this blended approach. They employ it in sectors like healthcare, power, and transport where physical and digital systems are closely connected.

Supply Chain Attacks

Critical infrastructure relies on a wide range of third-party vendors for hardware, software, and services. This interdependence makes supply chain attacks a persistent and growing threat.

Incidents like the SolarWinds compromise and the widespread impact of the Log4j vulnerability have shown how attackers can use trusted vendors as a backdoor into critical systems. These attacks often remain undetected for months.

A single breach can cascade across entire sectors, disrupting national operations and public services. 

Legacy System Exploits

Many industrial environments still depend on legacy systems running outdated or unsupported software. These systems, often contain known vulnerabilities like EternalBlue, lack segmentation from IT networks. These are difficult to patch due to compatibility issues.

As these systems are essential to operations, organisations often accept the risks rather than upgrade. These outdated systems often have hardcoded credentials, open ports, and weak monitoring, making them easy targets.

Once attackers breach the IT perimeter, they can move into OT systems. Without proper segmentation, these legacy components become a serious threat to national resilience. 

AI-Powered Threats

AI-driven threats are one of the biggest challenges for critical infrastructure today. Threat actors are using AI for reconnaissance, exploit development, and advanced social engineering tactics. Attackers use deepfake videos or voice messages to impersonate executives and trick employees into granting access or approving malicious actions.

In 2020, cybercriminals tricked a UAE-based bank into sending $35 million by using AI-generated voice cloning to mimic a company executive and approve a fake transfer.

Machine learning helps attackers map networks, identify weak points, and generate adaptive exploits in real time. This allows them to scale operations, shorten attack lifecycles, and evade traditional defences.  

How Organisations Can Defend Against These Threats

To defend against the growing cyber threats to critical infrastructure, organisations must adopt a proactive, layered defence strategy that includes real-time monitoring, asset visibility, network segmentation, red teaming, and adherence to international cybersecurity frameworks like NIST and IEC 62443.

Continuous Monitoring and Anomaly Detection  

Early detection helps stop attacks before they cause damage. Organisations should use real-time monitoring across both IT and OT systems. They must employ tools like SIEM platforms, threat intelligence feeds, and anomaly detection systems that spot unusual behaviour.

For example, a sudden surge in PLC (Programmable Logic Controller) traffic or an unexpected Modbus command should trigger an alert.

Machine learning tools can help SOC teams catch zero-day attacks, lateral movement, or data theft early. It's also important to combine IT and OT monitoring since many attacks move between both environments. 

Comprehensive Asset Inventories and Risk Assessments

Maintaining an up-to-date inventory of all hardware, software, and digital systems, both old and new, is a key first step.

Next, organisations should regularly assess risks by checking for vulnerabilities, business impact, and how easily assets could be exploited. These risk assessments must include physical devices, supply chain links, third-party tools, and cloud systems.

Linking known vulnerabilities (like CVEs or ICS-CERT alerts) to specific assets helps set patching priorities and plan fixes effectively.

Network Segmentation Between IT and OT Systems

Organisations must use network segmentation to stop lateral movement and contain breaches. This means isolating operational technology (OT) from corporate IT networks. This limits the ability of attackers to jump from exposed endpoints to critical control systems.

Techniques include:

• Firewall rules to enforce one-way data flow
• DMZ zones for controlled communication
• Air-gapping highly sensitive ICS components

Segmentation should also be logical, not just physical. It should be based on roles, data sensitivity, and business criticality. Microsegmentation using identity-based access rules further enhances containment in hybrid environments. 

Threat Intelligence, Red Teaming and Attack Simulation Exercises

Organisations should run tabletop exercises, penetration tests, and breach simulations tailored to sector-specific CNI threats. For instance, they could simulate a ransomware attack on SCADA systems or a deepfake-enabled phishing attempt on a procurement manager.

Organisations must test even the most secure environments. Red teaming exercises allow ethical hackers to mimic actual attack situations. These drills reveal hidden vulnerabilities, validate the efficacy of current defences, and test incident response under pressure. They also improve coordination and help fine-tune response protocols and communication plans in case of a real breach. 

Adoption of Regulatory Cybersecurity Frameworks and Standards

Organisations should align their programs with internationally recognised standards such as:

• NIST Cybersecurity Framework (CSF) – for identifying, protecting, detecting, responding, and recovering from cyber threats
• ISA/IEC 62443 – specific to securing industrial automation and control systems
• NIS2 Directive – relevant for EU-based entities, expanding on critical infrastructure security obligations
  
  

Adopting these frameworks strengthens an organisation’s ability to secure critical infrastructure systems. Regular gap assessments tailored to CNI environments help shift security from reactive patching to proactive, risk-based resilience across both IT and OT domains.