When a security incident occurs, the speed and effectiveness of your response determines the extent of damage. A well-prepared incident response plan is your organization's most critical security asset.
The Incident Response Lifecycle
Based on the NIST Incident Response framework, the process consists of four phases:
Phase 1: Preparation
Build and train your incident response team. Develop and document response procedures. Set up monitoring and detection tools. Establish communication channels and escalation procedures.
- Assemble an Incident Response Team (IRT)
- Document network architecture and asset inventory
- Establish evidence preservation procedures
- Set up an incident response toolkit
- Conduct tabletop exercises and drills
Phase 2: Detection and Analysis
Identify potential security incidents through monitoring, alerts, and reports. Analyze the scope and impact of the incident.
- Monitor SIEM alerts and log analysis
- Triage and prioritize incidents (P1-P4)
- Determine the attack vector and scope
- Document a timeline of events
- Classify the incident type
Phase 3: Containment, Eradication, and Recovery
Stop the incident from spreading, remove the threat, and restore normal operations.
- Short-term containment: Isolate affected systems
- Long-term containment: Apply patches, change credentials
- Eradication: Remove malware, close vulnerabilities
- Recovery: Restore systems from clean backups, verify integrity
Phase 4: Post-Incident Activity
Conduct a lessons-learned review. Update procedures based on findings. Share intelligence with the community (as appropriate).
Communication Plan
- Internal: Notify management, legal, HR, and PR as appropriate
- External: Regulatory notifications (GDPR 72-hour rule), law enforcement, affected individuals
- Media: Prepare statements, designate a spokesperson
Metrics to Track
- Mean Time to Detect (MTTD)
- Mean Time to Respond (MTTR)
- Mean Time to Contain (MTTC)
- Number of incidents by type and severity
- Root cause analysis findings
Key Takeaways
The best incident response plans are the ones that are practiced regularly. Conduct tabletop exercises quarterly and full simulations annually. Review and update your plan after every real incident. Remember: it's not a matter of if you'll face a security incident, but when.