In an increasingly connected world, OT networks face constantly evolving cyber threats. When an incident occurs, understanding what happened, how, and when is essential not only to restore operations but also to prevent it from recurring. This is where forensic analysis of industrial environments comes into play, combining investigative techniques with deep knowledge of automation and control systems.
Unlike traditional IT forensics, this field presents unique challenges that require specific methodologies, specialized tools, and a careful approach to avoid impacting production or physical safety.
In this article, we will explore what forensic analysis in OT environments is, its importance and challenges, and how InprOTech GUARDIAN can become a key ally to carry it out effectively and strengthen industrial cybersecurity.
What is it and what does it involve?
Forensic analysis is a methodical process aimed at investigating cybersecurity incidents to discover what happened, how it occurred, when, who was involved, and what impact it had.
It involves the collection, preservation, and analysis of digital evidence from industrial equipment and networks. The goal is to reconstruct the sequence of events of an incident, identify exploited vulnerabilities, and determine the origin of the attack — all without interrupting system operations.
Forensic analysis in industrial environments pursues several key objectives:
- Determine the origin and scope of the incident
- Identify weaknesses and propose security improvements
- Gather valid evidence that can be used in legal or regulatory processes
- Strengthen cyber resilience by learning from each incident to improve future responses.
Why is it necessary?
Industrial systems form the backbone of critical sectors such as energy, water, transportation, and manufacturing. A failure in these environments can have serious consequences: from production interruptions to economic impacts, environmental damage, or even risks to physical safety.
For this reason, having forensic processes is not just a best practice but a strategic necessity that enables:
Effective problem resolution
When an incident occurs, discovering the exact cause is essential. Forensic analysis makes it possible to identify whether it was a technical error, human failure, or cyberattack. This enables precise and rapid solutions, reducing downtime and operational impact.
Learning from mistakes
Each incident is an opportunity to improve. Forensic analysis helps document what happened and understand the root cause, generating knowledge that can be used to strengthen procedures, adjust configurations, and prevent similar future incidents.
Strengthening security and training
The forensic process not only protects systems but also contributes to training human teams.
By sharing findings and lessons learned, cybersecurity culture increases, making operators and technicians more aware of risks and more effective in detecting and responding to incidents.
Ensuring continuity and trust
In sectors where availability is critical, trust in operations is essential. A well-executed forensic analysis provides solid evidence that supports strategic decisions and demonstrates to clients, partners, and authorities that security is being managed responsibly and professionally.
Challenges and important considerations
OT systems are often designed to ensure operational continuity, not necessarily security, leading to unique challenges that must be considered during the investigation:
Poorly documented architectures
Many industrial environments use legacy or customized infrastructures, with devices that may have been in operation for more than 20 years.
These architectures often lack up-to-date documentation, making it difficult to understand system interconnections and locate evidence.
This requires forensic teams to conduct prior investigation, interview plant personnel, and have deep knowledge of industrial processes.
Complexity in data collection
Industrial devices such as PLCs, RTUs, or HMIs do not always log events in detail or use proprietary formats that are difficult to interpret. Additionally, stopping equipment to extract evidence is often not possible, as it could interrupt production or pose physical safety risks.
This requires non-invasive collection methods, such as passive network traffic captures or parallel analysis using system replicas.
Chain of custody
In an industrial environment, collected evidence may have legal value.
Therefore, it is essential to follow a strict chain of custody, documenting who accessed the evidence, how it was transported, and how it was stored.
This ensures that information remains intact and can be presented to authorities or auditors.
Vendor involvement
In many cases, industrial systems and equipment are managed by external vendors who possess critical information, such as configurations, firmware, or proprietary keys.
This means the forensic process may require coordination and confidentiality agreements, potentially delaying the investigation if a clear prior relationship does not exist.
Order of volatility
During evidence collection, it is important to follow the order of volatility, meaning prioritizing the capture of data that disappears the fastest (e.g., RAM memory).
If this order is not respected, key information needed to reconstruct the incident may be lost.
Order of evidence
In addition to volatility, a logical extraction and analysis sequence must be established to minimize system impact and facilitate later interpretation.
This involves planning which equipment will be examined first, how evidence will be named and stored, and which tools will be used in each phase to maintain consistency and traceability.
Phases of a forensic analysis
A forensic analysis is planned in phases, and each one must respect the chain of custody and order of volatility.
Asset identification
It is necessary to know what exists, where it is, and its level of criticality.
- Determine inventory by levels.
- Gather topology, versions, configurations, vendor contacts, etc.
- Define safe observation points such as port mirroring, TAPs, etc.
The objective of this phase is to thoroughly understand network assets and their context.
Anomaly detection
It is essential to identify signs of compromise without interrupting production.
- Detect alerts, unusual failures, shutdowns, unauthorized changes.
- Review logs and configurations of key devices.
- Perform network analysis with passive captures to detect anomalous behaviors, new connections, scans, port changes, etc.
- Verify time synchronization (NTP/PTP) to ensure proper event correlation.
The goal is to inventory suspicious events, prioritize them, and establish a timeline of occurrences.
Threat analysis
During this stage, detailed analysis of collected evidence is performed, correlating the attacker’s techniques, tactics, and procedures (TTPs). The main goal is to confirm hypotheses, validate identified risk scenarios, and detect exploited vulnerabilities.
Additionally, lessons learned are extracted and integrated into internal organizational processes, both technically and in personnel training programs. This strengthens the defensive posture and prevents similar future incidents.
Report generation
It is important to rigorously document the entire process. The recommended structure is:
- Executive summary: clearly and briefly explain what happened, what impact it had, and what decisions were made.
- Timeline and scope: establish a chronology showing how the incident unfolded and which systems were affected.
- Evidence and Indicators (IoCs): detail what evidence was collected, how, and where. Include integrity checks and chain of custody to ensure legal validity. Enumerate indicators of compromise found, such as suspicious files or IP addresses.
- Technical analysis: describe the TTPs used by the attacker, explaining how the attack occurred and progressed.
- Recommendations: provide concrete actions for containment, eradication, recovery, and prevention.
- Annexes: provide supporting materials useful for other analysts, such as captures, hashes, scripts, configurations, etc.
- Remediation and prevention: the objective of this final phase is to recover safely and reduce future probability/impact.
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- Safely and collaboratively contain affected devices/processes.
- Eradicate and recover with exhaustive and controlled testing to ensure proper service restoration.
- Implement preventive measures based on lessons learned.
- Train the team and update plans, playbooks, etc..
Analysis techniques
Different techniques are used to investigate incidents in industrial systems, each focused on a specific type of evidence. These tools allow valuable information to be gathered without interrupting operations, always respecting the chain of custody and order of volatility.
Network forensic analysis
Capture and analyze network traffic to identify the origin, destination, and content of communications.
Memory forensic analysis
Capture volatile memory from a device at a specific moment. Useful for discovering hidden processes, running malware, and temporary data not stored on disk.
Device forensic analysis
Review storage devices and other system components, such as logs and active processes. Ideal for detecting deleted, modified, or disguised files.
Malware analysis
Reverse engineering techniques to understand the behavior and capabilities of malicious software affecting the industrial environment.
Log analysis
Collect and correlate logs from various sources, such as PLCs, SCADA servers, or firewalls, to reconstruct events and detect suspicious activity.
InprOTech GUARDIAN
InprOTech GUARDIAN is a cybersecurity technology specifically designed to protect industrial networks and production environments. It operates by continuously monitoring and analyzing network traffic, using a combination of static rules, an IDS, artificial intelligence, and honeypots. This allows it to learn normal network behavior, detect anomalies in real time, identify device vulnerabilities, and automatically inventory network assets.
Thanks to these capabilities, Guardian not only helps prevent attacks and failures but also becomes an essential source of information during forensic analysis. By collecting and correlating industrial communication and event data, it provides a historical record that enables incident reconstruction, hypothesis validation, and better decision-making in response and OT cybersecurity improvement.
Conclusion
Forensic analysis in OT environments is essential to understand the origin and impact of incidents, enabling organizations to learn from them and reinforce industrial security. However, this process depends on the quality and availability of data collected during and before the attack.
In this context, InprOTech GUARDIAN positions itself as a strategic ally, providing continuous and precise visibility of the OT network.
Resources
[1] Forensic analysis in an industrial automation environment – Industrial Cybersecurity Center
[2] Secure access guide to field devices
[3] Forensic Analysis in Industrial Control Systems – Industrial Cybersecurity Center
[5] CyberOTworld: Forensic Analysis in OT environments after a Cyberattack (I)
[6] https://inprotech.es/importancia-de-la-formacion-y-concienciacion-en-ciberseguridad-ot/