Incident Response

What is Incident Response?

Incident Response (IR) is a structured process for handling information security incidents. It encompasses preparing the organisation to handle incidents, detecting and analysing events, containing the impact, eliminating the threat, restoring normal operations and drawing lessons for the future.

NIST SP 800-61 defines four phases of the IR process. Preparation - building the team, developing procedures, preparing tools and training. Detection and analysis - identifying the incident, determining its scope and criticality. Containment, eradication and recovery - stopping the threat from spreading, removing malware and restoring systems. Lessons learned - documenting the incident, root cause analysis and updating procedures.

An incident response team (CSIRT/CERT) can be internal, external or hybrid. Many organisations maintain an internal first-response team and engage external experts for complex incidents requiring specialist forensic analysis or ransomware group negotiations.

Why does it matter?

Every organisation will experience a security incident sooner or later. The difference between a controlled incident and a disaster often comes down to the quality of preparation and speed of response. Organisations with a mature IR process need on average four times less time to contain an incident and incur significantly lower costs compared to organisations without a response plan. NIS2 and DORA require formal IR procedures.

Related topics

• SOC
• Digital Forensics
• SOAR