Top 10 OT Forensics Tools for Incident Investigations

The industrial landscape has undergone a profound transformation, moving from air-gapped isolation to a highly interconnected IT/OT environment. This convergence, while driving efficiency through digital transformation, has simultaneously exposed critical infrastructure-from power grids and manufacturing plants to water treatment facilities-to an unprecedented level of cyber risk. Attacks like Stuxnet, Triton, and the recent waves of sophisticated ransomware targeting industrial operations have proven that the operational technology (OT) domain is no longer a peripheral concern, but a primary target.

When the worst happens, an effective response hinges entirely on a thorough Digital Forensics and Incident Response (DFIR) investigation. However, standard IT forensics tools and methodologies are often ill-suited for the unique, safety-critical, and proprietary nature of OT/Industrial Control Systems (ICS) and SCADA environments.

This is where specialized OT Forensics Tools become indispensable. They are the essential instruments that allow investigators to navigate the complexities of programmable logic controllers (PLCs), remote terminal units (RTUs), proprietary industrial protocols, and legacy systems to acquire, preserve, and analyze digital evidence without disrupting physical processes or compromising safety.

In this comprehensive guide for CyberSec Magazine readers, we move beyond generic IT solutions to highlight the Top OT Forensics Tools for Incident Investigations in today’s rapidly evolving threat landscape, focusing on the specialized capabilities necessary for a successful industrial cyber investigation.

The Unique Challenges of Operational Technology (OT) Forensics

Before diving into the tools, it’s crucial to understand why OT forensics is fundamentally different from IT forensics:

• Safety and Process Continuity: The primary concern in an OT environment is safety and operational uptime. Any forensic activity-especially data acquisition-must be non-disruptive. Shutting down a PLC or an entire production line to create a forensic image, a common IT practice, can lead to physical damage, safety hazards, and catastrophic financial loss.
• Proprietary and Heterogeneous Systems: OT networks are a patchwork of equipment from various vendors (Siemens, Rockwell, Schneider Electric, etc.), often running on proprietary operating systems (or none at all) and communicating via unique industrial protocols (Modbus, Ethernet/IP, Profinet, etc.). Standard IT tools often can’t parse or acquire data from these devices.
• Limited Logging and Storage: Field devices like PLCs and sensors have very limited computational power, memory, and logging capabilities. Critical information may be overwritten quickly or simply not recorded in a forensically useful format, making live memory analysis and network traffic analysis paramount.
• Legacy Systems and Patching: Many critical OT systems are decades old, run unpatched or end-of-life operating systems, and cannot be updated without extensive testing or risking operational failure. This creates a challenging environment for forensic data collection where system stability is extremely fragile.

Category 1: Specialized OT/ICS DFIR Platforms

These next-generation platforms are purpose-built to address the unique complexities of industrial environments, offering integrated capabilities that span asset visibility, threat detection, and forensic data correlation.

1. Dragos Platform

Dragos is often considered the gold standard for OT cybersecurity, and its platform’s forensic capabilities are a core strength.

• Core Value: ICS-Specific Threat Intelligence and Deep Protocol Analysis. The platform provides an unparalleled level of visibility into ICS protocol traffic, utilizing proprietary intelligence on industrial threat groups (e.g., Electrum, Hexane) and their specific Tactics, Techniques, and Procedures (TTPs).
• Forensic Functionality:
  • Automated Threat Playbooks: Maps detected intrusions directly to known ICS-centric attack behaviors (based on the MITRE ATT&CK for ICS framework).
  • Packet Capture (PCAP) and Log Correlation: Collects and analyzes full-fidelity network traffic across the Purdue Model, allowing for the rapid reconstruction of an attack timeline from initial IT network access to final OT manipulation.
  • Anomaly Detection: Its behavioral analysis engine spots unusual commands or deviations in industrial processes, providing high-fidelity Indicators of Compromise (IOCs) relevant to the physical process state.
• Why it Ranks High: The platform’s foundation in OT-native threat intelligence makes its forensic output highly actionable for industrial security teams.

2. Claroty Platform (e.g., Continuous Threat Detection)

Claroty’s solution portfolio is designed for the modern converged network, providing robust asset inventory and threat detection that directly feeds into forensic processes.

• Core Value: Comprehensive Asset Discovery and Vulnerability Context. Provides a deeply contextualized, real-time inventory of every OT, IoT, and IIoT asset, including make, model, firmware, and connectivity. This context is vital for scoping an investigation.
• Forensic Functionality:
  • Network Session Logging: Records and stores detailed metadata and session information for every communication on the OT network. This acts as a constantly running flight recorder for the industrial environment.
  • Remote Asset Data Acquisition: Where safe, it can assist in the non-disruptive collection of configuration files and memory snapshots from compatible devices.
  • Deep Packet Inspection (DPI): Offers full-spectrum DPI for hundreds of proprietary industrial protocols, translating complex protocol exchanges into human-readable events for forensic review.
• Why it Ranks High: Its ability to unify asset data, vulnerability context, and network flow details across the IT/OT boundary significantly accelerates the crucial initial phases of an incident investigation.

3. Tenable OT Security (formerly Indegy)

Focusing on the vulnerability and configuration side of OT security, Tenable provides critical forensic data points related to system changes.

• Core Value: Change Control Monitoring and Configuration Auditing. Tracks and logs all changes to PLC logic, controller configurations, and firmware.
• Forensic Functionality:
  • “Golden Image” Comparison: Allows investigators to compare the current, potentially compromised configuration of a controller against a known good, “golden” backup, instantly highlighting malicious modifications.
  • User Activity Monitoring: Logs all remote and local user access to OT assets, identifying unauthorized or suspicious administrative actions.
• Why it Ranks High: Attackers often manipulate PLC logic as the final step. Tenable provides the forensic evidence to prove what, when, and who changed the actual control logic.

Category 2: Network-Focused Analysis Tools (The Industrial “Flight Recorder”)

In OT/ICS forensics, network traffic is often the least volatile and most reliable source of truth. These tools excel at capturing, parsing, and analyzing the industrial chatter that tells the story of an attack.

4. Wireshark with Custom Protocol Dissectors

While a general-purpose network analyzer, its power is multiplied in OT forensics through specialized industrial protocol plugins.

• Core Value: Deep Protocol Visibility and Universal Availability. As the premier open-source network protocol analyzer, it captures and presents raw network traffic.
• Forensic Functionality:
  • Industrial Protocol Dissectors: When running specialized dissectors (e.g., for Modbus/TCP, S7Comm, DNP3), Wireshark can decode the operational meaning of packets, showing the forensic analyst not just bits and bytes, but the specific register values read/written or commands sent to a PLC.
  • Timeline Analysis: Allows filtering and analysis of captured traffic to build a chronological sequence of events, identifying unauthorized command injections.
• Why it Ranks High: It’s the essential tool for ground-up, packet-level evidence analysis, especially when commercial tools are unavailable or insufficient for an obscure or legacy protocol.

5. Security Onion (with Suricata/Zeek Integrations)

An open-source platform that integrates various security monitoring tools, making it a powerful, customizable solution for network-based forensics.

• Core Value: Unified Network Security Monitoring and Data Retention. It combines intrusion detection (Suricata), network security monitoring (Zeek, formerly Bro), and log management (Elastic Stack) into one platform.
• Forensic Functionality:
  • Zeek Logs: Generates high-fidelity transaction logs for all network activity, including connections, file transfers, and DNS queries, providing structured metadata that is easier to query than raw PCAP files.
  • Full Packet Capture (FPC): Provides the capability to store full network traffic streams, allowing investigators to go back and analyze the raw data for novel attacks.
• Why it Ranks High: Offers an enterprise-grade, yet customizable, platform for storing and querying the massive amounts of network telemetry generated in an industrial environment, making it excellent for long-term threat hunting and retrospective analysis.

Category 3: Host-Based and General-Purpose DFIR Tools (Adapted for OT)

Even in the OT world, Windows-based Human-Machine Interface (HMI) stations, engineering workstations, and historians are often the initial foothold for an attacker. Traditional forensics tools are adapted to handle these systems.

6. Magnet AXIOM / FTK Forensic Toolkit (FTK)

These industry-leading commercial platforms are primarily for IT/Endpoint forensics, but their ability to process host data is crucial for the OT layer 2 and 3 assets.

• Core Value: Comprehensive Endpoint Data Acquisition and Artifact Recovery. They excel at non-volatile data acquisition (disk imaging) and analysis from Windows and Linux endpoints.
• Forensic Functionality:
  • Registry and File System Analysis: Crucial for recovering evidence of lateral movement, malware staging, and execution on HMI and Engineering Workstations. This includes analyzing the Windows Registry for USB device connections, application execution keys, and service installations.
  • Memory Analysis Integration: Seamlessly integrates with memory analysis tools (like Volatility – see below) to correlate disk evidence with live-state data.
• Why it Ranks High: The digital footprint left on an HMI station is often the clearest link between the IT network and the compromised OT device. These tools are unmatched for analyzing that host-based evidence.

7. Volatility Framework / Kroll Artifact Parser and Extractor (KAPE)

These tools focus on the most transient but often most revealing form of evidence: volatile data.

• Core Value: Live Memory Analysis and Rapid Volatile Data Collection. Volatility analyzes memory images (RAM dumps) to reveal running processes, network connections, command history, and in-memory malware that disappears upon reboot. KAPE is excellent for rapid, targeted collection of critical files and registry keys.
• Forensic Functionality:
  • Malware Evasion Detection: Identifies process injection, rootkits, and hidden network sockets that an attacker might use to maintain persistence on a critical server.
  • Command Line History: Crucial for identifying the commands an attacker executed on a compromised server.
• Why it Ranks High: Given the sensitivity of OT devices, a full disk image is often not feasible. Live memory acquisition on a compromised HMI or historian server is often the safest and fastest way to find critical artifacts without interrupting the process.

Category 4: The PLC & Proprietary Device Specialists

This category represents the highly specialized area of extracting data directly from industrial controllers. As this is the most difficult and often proprietary task, few commercial tools exist, and the process often involves vendor-specific engineering software.

8. SCADA/PLC Vendor Engineering Software

The primary tool for interacting with a PLC is the same software used to program and maintain it (e.g., Siemens TIA Portal, Rockwell Studio 5000, Schneider Unity Pro).

• Core Value: The Only Way to Read PLC Logic and Configuration. These tools allow forensic analysts to connect to the controller and extract its running logic, variable tables, and fault logs.
• Forensic Functionality:
  • Logic Comparison: The software is used to download the running logic and compare it to the last known good version stored on the engineering workstation or a backup server.
  • Fault/Diagnostic Log Extraction: PLCs maintain a cyclic buffer of diagnostic events. These logs can often contain forensic gold, such as “Memory Violation,” “Program Download Complete,” or “Firmware Update.”
• Why it Ranks High: While not a “forensics tool” in the traditional sense, they are the most essential tools for acquiring the evidence that proves the attack’s final objective: manipulation of the physical process.

9. SANS ICS Forensics Collection (Custom Scripts/Frameworks)

In the absence of commercial tools, the SANS Institute and the ICS community have developed custom scripts and open-source frameworks for targeted evidence collection.

• Core Value: Vendor-Agnostic and Low-Impact Data Acquisition. These are often lightweight scripts designed to remotely pull specific data types (e.g., Windows Event Logs, Netflow data, registry keys) in a forensically sound manner.
• Forensic Functionality:
  • Remote Triage Collection: Scripts are used to quickly gather highly volatile data from endpoints without installing proprietary agents.
  • Specialized Protocol Interrogators: Custom tools built to send benign requests to specific industrial protocols to glean version or status information without causing disruption.
• Why it Ranks High: They are crucial for forensic readiness in OT environments, allowing responders to rapidly customize collection efforts for unique, complex systems without having to rely on a single vendor platform.

Category 5: SIEM/Log Management & Data Correlation

The final category includes the essential correlation and data management tools that tie all the disparate pieces of evidence together into a coherent narrative.

10. Splunk Enterprise Security / IBM QRadar (Adapted for OT)

Traditional SIEMs, when properly configured with specialized OT data connectors, become powerful correlation engines.

• Core Value: Event Correlation and Unified Timeline. SIEMs aggregate logs from IT Firewalls, Windows HMIs, OT-specific IDS/IPS, and network flow data.
• Forensic Functionality:
  • IT/OT Correlation: Enables the critical task of linking an IT event (e.g., a spear-phishing email opening on an engineer’s laptop) with a subsequent OT event (e.g., a failed login attempt on a PLC).
  • Long-Term Storage and Search: Provides the infrastructure to store years of log and event data, which is vital for post-incident analysis and identifying the initial breach point, which may have occurred months prior.
• Why it Ranks High: No OT incident is purely contained within the control network. A SIEM, when fed the right industrial data, is the essential tool for building the unified, end-to-end attack timeline from the initial vector to the final payload.

Key Considerations for Modern OT Forensics

Choosing and implementing the right tools is only half the battle. A successful OT forensics program must also adhere to best practices:

• Prioritize Safety Above All: The guiding principle for every action must be “Do No Harm.” Forensic tools must be deployed with extreme caution, often requiring approval from OT operations teams to ensure process stability is maintained.
• Establish a Digital “Safe Zone”: Create a dedicated, forensically sound network segment or DMZ that is completely separate from the production environment for staging and analyzing collected evidence. Never analyze evidence on a production system.
• Embrace Passive Collection: Rely heavily on passive network monitoring (PCAPs, NetFlow, Zeek logs) over active host-based collection. The less you touch the live system, the less risk you incur.
• Train for the Convergence: Your DFIR team must include or have direct access to personnel with deep industrial engineering and vendor-specific expertise. Understanding the difference between a normal alarm and a malicious command is impossible without this domain knowledge.
• Maintain a Forensic Jump Kit: Prepare an offline, pre-approved kit with lightweight, tested, and forensically sound data acquisition tools (like KAPE, Volatility, and custom scripts) to ensure a rapid response that bypasses system security controls only after a confirmed breach.

In the world of OT, an incident response is a race against both the attacker and the clock. Leveraging these specialized tools ensures that your organization can not only contain the threat but also meticulously reconstruct the attack, ultimately enhancing your defenses against the next, inevitable industrial cyber assault.