Incident Response Plan
Definition
An Incident Response Plan (IRP) is a documented, repeatable set of roles, processes, and communications used to prepare for, detect, analyze, contain, eradicate, and recover from information security incidents, while preserving evidence and capturing lessons learned. In ISO/IEC 27001:2022, an IRP supports the ISMS by defining how incidents are managed as an operational capability and by aligning with incident management controls in Annex A (including planning and preparation, response actions, learning, and evidence handling). A well-designed IRP specifies what constitutes an event versus an incident, how severity is determined, decision points for escalation, and how the organization coordinates technical response, business continuity, and stakeholder communications. It also includes requirements for logging actions, maintaining chain of custody for evidence, and conducting post-incident reviews to drive corrective actions and continual improvement. Equivalent concepts exist across other security and assurance approaches (e.g., incident handling guides, security incident management procedures, and response playbooks), but an IRP in ISO/IEC 27001 is typically governed, approved, tested, and maintained as a controlled ISMS document.
Real-World Examples
Startup phishing containment
A SaaS startup detects a compromised mailbox, resets credentials, revokes sessions, reviews access logs, and notifies affected customers using pre-approved templates and escalation paths in the IRP.
Ransomware response at an enterprise
A large organization isolates infected endpoints, restores systems from backups, engages legal and crisis communications, preserves forensic images, and runs a lessons-learned review to update controls and procedures.
Cloud misconfiguration data exposure
A scaleup discovers a storage bucket exposure, immediately restricts access, confirms scope with audit logs, documents evidence handling, and completes a post-incident action plan to prevent recurrence.
An IRP is a documented set of steps, roles, and decision points used to handle security incidents consistently, covering preparation, detection, containment, recovery, communications, and improvement.
It should include incident definitions, severity criteria, team roles, escalation paths, response workflows, communication procedures, evidence handling, required records, testing cadence, and post-incident review steps.
Define incident types and severity levels, assign responsibilities, map response phases, establish tooling and logging requirements, create communication and escalation procedures, and validate the plan through exercises and updates.
Common phases include preparation, identification, triage and analysis, containment, eradication, recovery, and lessons learned, with documentation and evidence preservation throughout the lifecycle.
Typically it includes security, IT operations, engineering, legal, privacy, communications, and leadership, with defined roles for incident commander, technical leads, evidence custodian, and stakeholder communications.
The IRP is the overarching governance document describing roles, escalation, and process, while playbooks are scenario-specific runbooks (e.g., ransomware, phishing) with detailed technical steps.
Test it at least annually and after major changes or incidents, and review/update whenever lessons learned, new threats, organizational changes, or tooling updates affect response effectiveness.
Use predefined communication channels, approvals, and message templates, coordinate leadership and legal review, maintain a single source of truth for status, and document what was communicated and when.
Collect timelines, alerts, logs, indicators of compromise, system images where appropriate, decisions made, actions taken, and communications, while maintaining chain of custody and access controls for evidence.
Yes—smaller teams can use a lighter plan, but it should still define who does what, how to escalate, how to contain and recover, how to communicate, and how to record evidence and lessons learned.
| Version | Date | Author | Description |
|---|---|---|---|
| 1.0.0 | 2026-02-26 | WatchDog Security GRC Wiki Team | Initial publication |
