Incident Response
2025-01-01

Overview#

Incident response (IR) coordinates people, process, and technology to limit damage when security events occur. A strong IR function rehearses likely scenarios, defines clear roles, and keeps communication channels open to shorten dwell time and recovery.

Core objectives#

  • Establish an IR policy with roles, decision rights, and communication rules (including legal and privacy).
  • Classify incident severity and pre-assign response playbooks for common scenarios (e.g., ransomware, BEC, data loss).
  • Preserve evidence with defensible chain-of-custody and logging practices.
  • Drive post-incident learning so fixes and monitoring gaps are addressed.

Implementation notes#

  • Maintain a 24x7 on-call rotation with clear escalation paths and backup contacts.
  • Pre-stage tooling access: EDR isolation, log retrieval, forensics kits, and privileged break-glass accounts.
  • Define communication templates for executives, regulators, customers, and internal stakeholders.
  • Run tabletop exercises at least twice per year and capture actions in a tracked backlog.

Operational signals#

  • Leading indicators: mean time to acknowledge (MTTA) and mean time to contain (MTTC) for high-severity alerts.
  • Lagging indicators: repeat incidents of the same root cause, missed regulatory notification windows, or data-loss impacts.
  • Feedback loops: blameless post-incident reviews with remediation assignments, due dates, and verification checks.

Runbook essentials#

  • Triage flow: validate alert → determine scope and severity → contain (isolate endpoints, disable accounts, block IOCs) → collect evidence → eradicate and recover.
  • Legal/privacy review for potential personal data exposure and contractual reporting obligations.
  • Documentation: timeline, decisions, artifacts collected, and final lessons learned stored in a searchable system.
  • Detection engineering and threat intelligence improve signal quality and context during investigations.
  • Business continuity and disaster recovery plans accelerate restoration after major incidents.
  • Security awareness keeps staff ready to report suspicious activity early.