Full Report
This webinar reviews recent government directives, clears up the controversy, and introduces practical approaches to islanding. We evaluate islanding advice in the context of the emerging era of AI-based zero-day exploits. The post Keeping OT Going When IT Goes Dark appeared first on Waterfall Security Solutions.
Analysis Summary
# Best Practices: Islanding OT Networks for Cyber Emergencies
## Overview
These practices address the critical need for "islanding"—the intentional, rapid, and sustained disconnection of Operational Technology (OT) networks from Information Technology (IT) networks. This strategy ensures that critical infrastructure functions remain operational even when the IT environment is compromised by ransomware or AI-based zero-day exploits.
## Key Recommendations
### Immediate Actions
1. **Conduct a Dependency Audit:** Identify all cross-domain dependencies. Document every service that crosses from IT to OT (e.g., Active Directory, DNS, NTP, Windows Update, antivirus mirrors).
2. **Define "Islanding" Triggers:** Establish clear criteria for when the "kill switch" is pulled. Do not wait for manual approval during a fast-moving ransomware event.
3. **Validate Manual Overrides:** Ensure that all critical physical processes can be operated manually or via local HMI (Human-Machine Interface) if the wide-area network or IT-integrated systems fail.
### Short-term Improvements (1-3 months)
1. **Eliminate Logical Dependencies:** Migrate essential OT services (like DNS and authentication) so they reside physically and logically within the OT perimeter, rather than relying on IT-based servers.
2. **Deploy Physical Separation Hardware:** Shift from purely logical separation (firewalls/VLANs) to physical separation technologies (e.g., Unidirectional Gateways) to prevent lateral movement of AI-driven exploits.
3. **Develop an "Islanded Ops" Runbook:** Create a specific SOP for operating the plant in a disconnected state for up to 90 days, including manual data logging and local maintenance schedules.
### Long-term Strategy (3+ months)
1. **Resilience by Design:** Architect the OT environment so that "Islanded" is the default state for high-risk periods, rather than an emergency exception.
2. **Procurement Requirements:** Mandate that all new OT equipment must be capable of full functionality without a persistent cloud or IT-corporate connection.
3. **Legal Liability Alignment:** Ensure islanding capabilities meet emerging "reasonable security" legal standards to mitigate post-breach litigation risks.
## Implementation Guidance
### For Small Organizations
- **Focus on Essential Services:** Ensure the PLC/HMI network can run if the office internet/Wi-Fi is cut. Use local USB backups for critical configuration files.
### For Medium Organizations
- **Hardware-Based Isolation:** Implement physical air-gapping or unidirectional gateways at the IT/OT interface to ensure IT breaches cannot physically propagate to the plant floor.
- **Redundant Historians:** Maintain an OT-resident historian so data continues to be collected even if corporate reporting tools are offline.
### For Large Enterprises
- **Distributed Autonomy:** Design each facility to operate as a "sovereign island." Centralized SOCs should receive data, but the facility must not depend on the SOC or Corporate Data Center for operational commands.
- **CI-Fortify Alignment:** Adopt the 3-month sustained isolation capability recommended by international government directives.
## Configuration Examples
*While specific CLI code is not provided in the webinar summary, the following architectural configuration is recommended:*
- **Identity Management:** Deploy a standalone OT Active Directory Forest with no trusts to the IT Forest.
- **Time Sync:** Install a local GPS-based NTP stratum-1 clock within the OT network to avoid reliance on IT-based time servers.
- **Update Management:** Use a "Sanitize and Transfer" station (sheep-dip) for bringing software updates into the islanded zone via physical media or unidirectional bridge.
## Compliance Alignment
- **CI-Fortify Initiative:** Direct alignment with government directives for critical infrastructure resilience.
- **NIST SP 800-82:** Guidelines for Industrial Control Systems (ICS) Security.
- **IEC 62443:** Standards for the security of Industrial Automation and Control Systems.
- **NERC CIP:** Requirements for bulk power system security.
## Common Pitfalls to Avoid
- **Cloud Dependencies:** Assuming a system is "local" when it actually requires a cloud heartbeat to function.
- **The "Firewall Fallacy":** Relying solely on software-defined firewalls, which can be misconfigured or bypassed by zero-day exploits.
- **Ignoring the 3-Month Rule:** Planning for only a few hours of downtime. Modern cyber-recoveries (e.g., after major ransomware) often take weeks or months.
## Resources
- **CI-Fortify Initiative Guidelines:** Government-backed OT resilience framework.
- **Waterfall’s Islanding Operator Planning Guide:** hxxps://waterfall-security[.]com/islanding-guide (Ref: Webinar resource).
- **Waterfall Self-Assessment Guides:** Tools for evaluating OT/IT dependency risks.