Operational Technology (OT) and Information Technology (IT) now share the same threat landscape, but the consequences of failure in OT are far more physical, expensive, and politically sensitive than in pure IT environments.
OT vs IT cybersecurity: why the stakes are different
IT security is fundamentally about protecting data, privacy, and business applications, while OT security is about keeping physical processes safe, reliable, and predictable. In IT, you can usually tolerate short outages to remediate a threat; in OT, stopping a turbine, a bottling line, or a pipeline may be economically or even societally unacceptable.
Key contrasts:
- IT focuses on confidentiality and data integrity for endpoints, servers, SaaS, and cloud workloads. OT focuses on availability, safety, and deterministic behaviour for PLCs, RTUs, DCS, SCADA, and safety‑instrumented systems.
- IT environments rely on frequent patching and agile change management, whereas OT environments have rare maintenance windows tightly bound to production schedules.
- IT threats are dominated by financially motivated crime groups, while OT threats increasingly involve nation‑states and highly resourced groups targeting critical infrastructure.
| Aspect | IT security focus | OT security focus |
|---|---|---|
| Primary objective | Data protection, privacy, business continuity | Operational continuity, physical safety, process integrity |
| Typical assets | Servers, laptops, SaaS, databases | PLCs, RTUs, SCADA, DCS, safety systems, sensors |
| Risk of failure | Data loss, fraud, reputational damage | Physical damage, outages, safety incidents, environmental harm |
| Patch/change cadence | Frequent, often automated | Infrequent, tightly scheduled maintenance windows |
| Threat actors | Cybercrime groups, insiders | Nation‑states, ICS‑focused groups, cyber‑physical extortion |
| Architectural priority | Connectivity and usability | Segmentation, isolation, determinism |
OT attacks and malware that changed the game
A small set of industrial malware families reshaped how we think about OT risk.
Stuxnet
Stuxnet targeted Iranian nuclear enrichment, manipulating Siemens PLCs that controlled centrifuges while feeding operators fake normal readings. It used multiple zero‑days, spread via removable media and networks, and implemented highly tailored PLC payloads to physically degrade equipment.
BlackEnergy and GreyEnergy
BlackEnergy and its successor GreyEnergy are linked to disruptive attacks on Ukrainian critical infrastructure, including the 2015 power outages. These toolsets combined ICS reconnaissance, lateral movement, and destructive components to wipe systems and interfere with power distribution.
Havex (Energetic Bear / Dragonfly)
Havex (Backdoor.Oldrea) was used by the Energetic Bear/Dragonfly group in widespread espionage and sabotage campaigns against energy and industrial targets. It famously abused software supply chains by compromising legitimate ICS installers to gain access, then performed ICS network scanning and data exfiltration.
Industroyer / CRASHOVERRIDE
Industroyer is an ICS‑tailored malware framework believed to have been used against Ukraine’s power grid in 2016. It implemented native support for industrial power protocols to interact directly with grid equipment, enabling automated manipulation of breakers and substations.
Triton / TRISIS
Triton targeted Triconex safety‑instrumented systems, attempting to disable or manipulate safety functions in a petrochemical facility. This raised the prospect of malware engineered to facilitate catastrophic physical incidents by turning off the last line of defence.
Pipedream, Duqu and others
More recent frameworks such as Pipedream, plus families like Duqu, highlight continued investment in ICS‑aware toolchains with modular capabilities spanning initial access, ICS reconnaissance, and payload delivery. Collectively, these campaigns demonstrate that OT attacks are no longer hypothetical; they’re repeatable patterns with maturing tradecraft.
The financial and systemic cost of OT compromise
OT cyber incidents involve more than ransom demands or regulatory fines; they cascade across economies and supply chains.
- OT cyber risk exposure has been estimated in the hundreds of billions of dollars globally when you factor in direct damage, supply‑chain disruption, and systemic impacts.
- Indirect costs such as prolonged downtime, safety investigations, environmental remediation, and production loss often exceed immediate incident‑response spend.
- Controls with the greatest risk‑reduction effect include robust incident‑response capability, defensible segmentation, and continuous ICS network visibility, each associated with measurable reductions in modeled OT risk.
For boards and CISOs, this repositions OT security from “compliance overhead” to a major business‑continuity and systemic‑risk concern.
Modern attacker tradecraft: encryption, AI, and memory
Threat actors are aggressively exploiting weaknesses in traditional controls, particularly in converged IT/OT environments.
Encrypted C2 and payload delivery
- Malware increasingly uses TLS or custom encryption on command‑and‑control and data‑exfiltration traffic, hiding malicious behaviour inside “normal‑looking” HTTPS streams.
- Some campaigns rely on bespoke encryption schemes that are impractical to decrypt at scale, forcing defenders to decide whether to block “unknown encrypted” traffic at the perimeter.
AI‑assisted and AI‑resilient malware
- Operators of campaigns such as EvilAI and related families have used AI tooling to generate malware code and surrounding infrastructure that appears clean and legitimate to static scanners.
- AI is also used to generate realistic‑looking apps and websites, and to continually mutate code so that each build differs enough to evade signature‑based tools while retaining core malicious functionality.
Fileless and memory‑resident techniques
- Many modern payloads emphasise fileless execution using script engines, PowerShell/WMI, in‑memory loaders, and reflective DLL injection to minimise disk artefacts.
- Endpoint tooling must therefore instrument process, memory, and script activity—particularly on jump hosts and engineering workstations that bridge IT and OT—to detect these techniques.
These trends are especially problematic in OT segments that lack full endpoint visibility and rely heavily on network‑only controls.
SIEM, logging, and telemetry: why OT is hard to see
Centralised logging and analytics are the backbone of most detection and response strategies, but OT introduces distinctive gaps.
Logging challenges in OT
- Legacy PLCs and RTUs may not produce security‑relevant logs at all, or they emit proprietary formats that are hard to ingest into SIEMs.
- Critical ICS events may occur on serial links or within proprietary fieldbuses that are invisible to standard IP‑based collectors.
- Resource‑constrained devices cannot tolerate heavy agents, verbose logging, or frequent polling without jeopardising performance and supportability.
Getting data into SIEMs
- Organisations often rely on OT‑aware sensors and protocol decoders that sit on SPAN/TAP points and translate ICS protocol activity into enriched events for SIEMs.
- Even when integration is possible, SIEM platforms are not designed as high‑fidelity OT historians; they may struggle with volume, retention, and deep contextual analytics without augmentation from specialised tools or data lakes.
Many OT SOCs adopt a layered model where SIEM is the aggregation and correlation layer, but deep ICS protocol analytics, asset inventory, and behavioural modelling occur in dedicated OT security platforms.
Why XDR, IDS, and IPS matter in converged OT environments
As threats evolve, blue teams are relying on a combination of signature‑driven and behaviour‑driven technologies.
IDS / IPS
- Network IDS/IPS examines traffic for known malicious signatures and anomalies, applying both pattern matching and heuristic/behavioural logic.
- Modern attacks evade classic signatures via new domains, zero‑days, encryption, perimeter avoidance, internal lateral movement, and credential abuse, all of which degrade traditional IDS/IPS effectiveness if it is not paired with deeper analytics.
XDR (Extended Detection and Response)
- XDR platforms extend endpoint‑style telemetry (processes, files, memory, registry, connections) across endpoints, servers, cloud, and sometimes OT‑adjacent systems, then correlate signals with network and identity data.
- Effective XDR gives defenders a single investigation plane that spans IT and the OT perimeter, helping to detect lateral movement from corporate networks into OT DMZs and engineering stations.
EDR and endpoint visibility
- Endpoint Detection and Response (EDR) provides continuous monitoring of host behaviour, including memory and script execution, which is essential to catching fileless and in‑memory techniques that never hit disk.
- In OT, you often deploy EDR selectively (for example, on jump servers, HMIs, and engineering workstations) and compensate for non‑instrumented devices with network‑centric monitoring and strict access‑control policies.
Together, layered IDS/IPS, XDR/EDR, OT‑aware sensors, and a SIEM/SOAR stack form a defence‑in‑depth architecture capable of spotting both commodity ransomware and highly tailored ICS campaigns.
Defensive AI: behaviour‑based analytics for OT
Defenders are also turning to AI and behaviour analytics to compensate for encrypted traffic, polymorphic malware, and logging gaps.
- Network‑centric AI platforms profile normal communications between ICS assets (for example, which engineering station writes which coils on which PLC, at what times) and alert on deviations such as unexpected write operations or protocol misuse.
- Machine‑learning‑driven anomaly detection helps surface lateral movement, privilege escalation, and stealthy C2 that would not match known signatures, particularly in environments where traffic is partially or fully encrypted.
- These tools complement—but do not replace—traditional controls; they still depend on high‑quality telemetry and tuned baselines to avoid alert fatigue.
For OT, behaviour‑based analytics must be tuned with process knowledge so that legitimate process variations do not generate constant false positives.
OT redundancy and legacy constraints: hidden risks
OT systems are engineered for resilience, but the same features that deliver resilience can conceal compromise.
- Redundant controllers and networks can allow attackers to compromise a warm‑standby asset that only becomes active during failover, delaying detection until a stressed moment.
- Dual‑homed assets or redundant comms paths can unintentionally bypass firewalls and segmentation, opening “shadow” routes from IT into OT.
- Legacy operating systems and unpatchable devices force reliance on compensating controls such as jump hosts, strict allow‑listing, and protocol break‑points, which require strong governance and engineering collaboration.
Understanding your own redundancy topology and legacy constraints is essential to realistic threat modelling and to designing controls that don’t break safety or uptime.
Checklist for senior cyber professionals securing OT
For heads of security, OT security leads, and senior blue‑teamers, the following checklist can be used as a practical baseline.
Architecture and governance
- Maintain a current, business‑approved network segmentation model separating IT, DMZ, OT, and safety‑critical zones.
- Enforce single, monitored pathways between zones (jump hosts, data diodes, or tightly controlled firewalls).
- Document and review all dual‑homed systems and redundant pathways for potential segmentation bypasses.
- Establish joint governance between IT security, engineering, and operations for change control and incident response.
Visibility and telemetry
- Deploy ICS‑aware passive monitoring sensors on key OT network segments.
- Ensure logging for firewalls, remote‑access systems, jump servers, and engineering workstations feeds into the SIEM.
- Implement selective TLS inspection on IT and OT DMZ boundaries where latency and determinism allow.
- Use asset‑discovery tools capable of identifying OT devices, firmware versions, and protocol usage.
Detection and response capability
- Implement XDR/EDR coverage on all IT assets that can reach OT, and on critical OT‑adjacent hosts (HMIs, historians, engineering stations).
- Deploy network IDS/IPS tuned with ICS signatures and anomaly‑detection for critical conduits.
- Integrate OT telemetry into SIEM and, where possible, SOAR for playbook‑driven response.
- Test incident‑response playbooks that include engineering and operations, with realistic OT scenarios (for example, ransomware in IT necessitating OT shutdown decisions).
Hardening and access control
- Enforce MFA and strong account hygiene for remote access into OT networks.
- Apply strict role‑based access control and least privilege for engineering functions (programming PLCs, modifying safety logic).
- Implement application and script allow‑listing on OT‑adjacent Windows systems.
- Review and harden vendor remote‑support arrangements, including jump hosts, VPNs, and contracts.
Threat‑informed defence
- Map known ICS malware TTPs (Stuxnet, Havex, BlackEnergy, Industroyer, Triton, Pipedream) to MITRE ATT&CK for ICS and verify you have at least one preventive or detective control per technique.
- Subscribe to OT‑focused threat intelligence and ensure intelligence is operationalised into rules, detections, and hunts.
- Run periodic purple‑team exercises against OT‑adjacent assets using realistic adversary emulation plans.
What CISOs should specifically pay attention to
From a CISO perspective, OT cyber risk sits at the intersection of safety, operations, and regulation.
- Business‑impact modelling: Quantify the production, safety, and reputational impact of losing key OT processes to inform investment and cyber‑insurance discussions.
- Board‑level reporting: Present OT cyber risk as part of overall operational‑risk reporting, not as a niche technical concern.
- Regulatory alignment: Track sectoral regulations and guidance for critical infrastructure, which increasingly mandate specific OT security controls and incident‑reporting obligations.
- Supply‑chain exposure: Evaluate vendor and integrator access rigorously in light of supply‑chain compromises such as Havex and similar campaigns that weaponised trusted software and support channels.
- Resilience vs. security trade‑offs: Ensure cyber controls do not undermine safety or process resilience, and vice versa; security decisions in OT must be co‑designed with engineering and safety stakeholders.
Framing OT security in terms of operational resilience, safety, and systemic risk anchored in concrete malware examples and modern evasion techniques helps senior leaders and practitioners build programmes that are both technically credible and business‑aligned.
References
XM Cyber – OT vs. IT Cybersecurity: Differences, Similarities and Everything in Between[xmcyber]
Cyberday – IT and OT Cyber Security: Different Environments, Same Threats[cyberday]
Reddit – OT vs. IT Cybersecurity (practitioner discussion)[reddit]
Cyber Insurance Academy – 5 Cyberattacks That Changed the World[cyberinsuranceacademy]
Silicon Republic – Cyberattackers Are Getting More Evasive: How Can Cybersecurity Keep Up?[siliconrepublic]
Industrial Cyber – OT Cyber Risk Could Exceed $300 Billion[industrialcyber]
Muninn – IT vs. OT Cybersecurity: Understanding the Key Differences[muninn]
McAfee / Google Cloud – Triton Malware and ICS‑Tailored Attacks[mcafee]
ACM – Automating ICS Malware Analysis with MITRE ATT&CK[dl.acm]
Dark Reading – A Brief History of ICS‑Tailored Attacks[darkreading]
Wikipedia – Havex[en.wikipedia]
Alphatechs – Noteworthy Threats in ICS Malware Analysis[alphatechs]
Vectra – What Is IDS/IDPS?[vectra]
Sysdig – EDR vs. XDR vs. SIEM vs. MDR vs. SOAR[sysdig]
Google Cloud – Attackers Deploy New ICS Attack Framework: TRITON[cloud.google]
Trend Micro – EvilAI Operators Use AI‑Generated Code and Fake Apps[trendmicro]
Sysdig (alt) – EDR vs. XDR vs. SIEM vs. MDR vs. SOAR[it.sysdig]