Disaster Recovery Planning: Continuity After a Cyber Attack

Disaster recovery (DR) planning ensures that your organization can restore critical systems and data after a catastrophic event, whether a ransomware attack, natural disaster, hardware failure, or cloud provider outage. Organizations without tested DR plans experience average downtime of 21 days after a ransomware attack, with recovery costs averaging $1.85 million. Organizations with tested plans recover in days, not weeks.

Key Concepts

Recovery Time Objective (RTO): The maximum acceptable time for restoring a system after a disruption. An RTO of 4 hours means the system must be operational within 4 hours. Different systems have different RTOs based on business criticality.

Recovery Point Objective (RPO): The maximum acceptable data loss measured in time. An RPO of 1 hour means you can afford to lose up to 1 hour of data. This determines backup frequency: an RPO of 1 hour requires at least hourly backups.

Maximum Tolerable Downtime (MTD): The absolute maximum time a business function can be unavailable before the organization faces existential consequences.

Building the Plan

Business Impact Analysis (BIA). Identify critical business functions, the systems that support them, and the financial and operational impact of their unavailability. This analysis determines RTO and RPO for each system and prioritizes recovery order.

Recovery strategies. For each critical system, define how it will be recovered. Options include: restoring from backups to replacement hardware, failover to a hot standby in a secondary data center, failover to a cloud disaster recovery environment, or manual workarounds while systems are restored.

Backup architecture. Ensure backups support your RPOs. Follow the 3-2-1-1-0 rule: 3 copies, 2 media types, 1 offsite, 1 immutable, 0 errors verified through testing. See our backup strategy guide for detailed implementation.

Communication plan. Define how employees, customers, partners, and regulators will be notified during a disaster. Include templates, contact lists, and alternative communication channels in case primary systems are down.

Recovery procedures. Document step-by-step recovery procedures for each critical system. Include system dependencies, recovery order, validation checks, and responsible personnel. Procedures should be detailed enough that someone unfamiliar with the system can execute them.

Testing

Paper test. Review procedures for completeness and accuracy without executing any actions. Identifies obvious gaps.

Walkthrough test. The recovery team walks through procedures verbally, identifying dependencies, timing issues, and missing steps.

Simulation test. Execute the recovery process in a test environment. Restore systems from backup, verify data integrity, and measure actual RTO achievement.

Full interruption test. The most thorough test: actually fail over to disaster recovery systems. This is disruptive and risky but provides the highest confidence.

Test at least quarterly, rotating between test types. After every real incident, review and update the plan.

For the incident response procedures that precede disaster recovery, see our incident response plan guide. For the backup strategy underlying recovery, explore our 3-2-1 backup guide.

Cloud-Based Disaster Recovery

Cloud services have made disaster recovery accessible to organizations of all sizes. AWS, Azure, and GCP all offer disaster recovery services that replicate critical workloads to secondary regions. Cloud DR eliminates the need for dedicated secondary data center hardware, replacing capital expenditure with operational costs that scale with actual usage.

For smaller organizations, even basic cloud backup services provide meaningful DR capability. Automated backup of critical systems to a different cloud region, combined with documented recovery procedures, provides a DR foundation that would have required significant infrastructure investment a decade ago. The key is testing: a backup you have never restored from provides false confidence.

Communication During a Disaster

When primary systems are down, how will you communicate with employees, customers, and partners? Establish backup communication channels that do not depend on your primary infrastructure: personal cell phone trees for leadership, a pre-configured emergency communication platform (Everbridge, AlertMedia), and pre-written templates on printed copies stored in multiple locations.