The U.S. National Institute of Standards and Technology (NIST) released Special Publication 1339, an OT (Operational Technology) Backup Quick Start Guide aimed at helping industrial organizations strengthen cyber resilience and recovery readiness. The guidance emphasizes that OT backups are a critical component of incident response and recovery, enabling organizations to maintain reliable system operations, sustain critical functions, and restore services following cyber incidents.
NIST advises organizations to begin by identifying OT assets essential to operations, including programmable logic controllers, distributed control systems, SCADA (supervisory control and data acquisition) servers, human-machine interfaces, firewalls, and other devices containing critical configurations or operational data. The publication also stresses that effective OT backup strategies extend beyond simply storing copies of data.
Additionally, NIST SP-1339 recommends integrating backups into change and risk management processes, maintaining both on-site and off-site redundant storage, validating backup integrity through hashing and engineering verification methods, and routinely testing restoration procedures on non-production systems. The guidance further highlights the importance of preserving engineering documentation, spare parts, firmware, configuration files, and specialized software to accelerate recovery, particularly in environments where legacy systems and supply chain delays can complicate restoration efforts.
Organizations should identify all critical OT assets and maintain an up-to-date inventory to prioritize backup and recovery efforts based on operational importance. They should also document the essential files, software, configurations, and spare parts needed for system restoration, while ensuring compatible replacement hardware is readily available to minimize recovery delays and supply chain disruptions.
To identify assets critical to operations, the NIST SP-1339 document mentioned that organizations should determine the files, software applications, and spare parts required to restore their environment. These assets may include program and logic files, configuration data, input/output lists, firmware, human-machine interface graphics files, license keys, vendor configuration tools, support documentation, operating system or virtual machine images, and any supporting software needed for redeployment.
Organizations should also establish a spare parts plan to ensure critical components are readily available to meet recovery time objectives. The plan should help reduce the impact of supply chain delays and ensure replacement hardware remains compatible with digital backups, enabling faster and more effective system recovery.
NIST identified that organizations should identify the backups required for each asset by defining backup frequency, storage media, and storage locations based on how often data changes, the type of system, and associated risks. They should account for OT-specific backup constraints, particularly those involving legacy equipment with limited availability or weaker security features, and incorporate these factors into backup and recovery planning. Backup-related changes should also be reviewed through change management processes.
In addition, organizations should establish clear media labeling and indexing procedures, maintain redundant backups both on-site and off-site, and implement measures such as hashing, encryption, or write-once media to preserve backup integrity and availability. They should also ensure backup media is protected from unauthorized access, modification, or destruction.
The NIST SP-1339 identified that organizations should establish clear procedures for backup and recovery by obtaining vendor manuals, software utilities, and technical guidance to support restoration operations. These vendor-recommended procedures should be adapted and integrated into the organization’s backup, recovery, and change management processes to align with specific operating environments and safety requirements.
They should also maintain specialized engineering software, cables, and licenses needed for immediate onsite response. In addition, organizations should create a process for storing file hashes of backup content to verify backup integrity before restoration begins. Backup strategies should include hot backups for immediate failover with real-time replication, warm backups for rapid recovery using regularly updated data, and cold backups for offline data or spare parts that require full system rebuilding before services can be restored.
The NIST document detailed that organizations should conduct regular backup restoration tests on non-production systems to validate backup media reliability, practice recovery procedures, and confirm the functional integrity of restored systems. Backup integrity should be verified using cryptographic hashing where possible. For OT assets, integrity validation should also include approved engineering methods, such as offline-to-online logic comparisons or native software verification.
Organizations should further refine backup and restoration processes, procedures, and documentation based on lessons learned during testing. These updates can help improve recovery speed, strengthen restoration accuracy, and enhance preparedness during an actual emergency.
Furthermore, organizations should adopt a layered approach to recovery preparation by regularly ensuring that supplemental engineering documents are available in both printed and electronic formats to support incident response and restoration efforts.
They should also maintain documentation that can accelerate verification, validation, and troubleshooting during system recovery. This may include logic print files, input/output lists, equipment specification sheets, Safety Requirements Specifications, control narratives, cause-and-effect matrices, network diagrams, wiring diagrams, and historian configurations.
