Security Incident Response Playbook

What This Playbook Covers

Security incidents require a structured, repeatable response to minimize impact and restore control quickly. This playbook explains how to identify, contain, investigate, remediate, and recover from incidents within Microsoft 365 environments.

Important: Without a defined response process, organizations react inconsistently, increasing damage, downtime, and risk exposure during security incidents.

When This Playbook Is Used

Suspicious Account Activity

Unexpected sign-ins, MFA fatigue, impossible travel, or abnormal user behavior is detected.

Phishing Or User Compromise

A user reports phishing, a malicious link, or an account is suspected to be compromised.

Potential Data Exposure

Sensitive data may have been accessed, shared, altered, or exfiltrated improperly.

Execution Steps

01

Identify The Incident

Validate indicators, confirm the event is not a false positive, and determine the initial scope of affected users, data, and systems.

02

Contain The Threat

Disable compromised accounts, revoke sessions, isolate affected endpoints, and block malicious activity to prevent additional damage.

03

Preserve Evidence

Retain logs, alerts, email artifacts, identity activity, and other relevant evidence needed for investigation and review.

04

Investigate Root Cause

Determine how the incident occurred, what systems or identities were involved, and whether persistence or lateral movement remains.

05

Remediate And Recover

Remove malicious artifacts, reset credentials, restore secure configurations, and validate that affected systems are back in a controlled state.

06

Review And Improve

Document lessons learned, identify control gaps, and update response procedures to reduce the likelihood and impact of future incidents.

Operational Requirements

Defined Response Roles

Clear ownership must exist for detection, containment, investigation, recovery, and communications during an incident.

Logging And Visibility

Systems must provide sufficient logging, alerting, and monitoring to support rapid detection and investigation.

Controlled Administrative Access

Privileged access must be limited, monitored, and protected to avoid additional compromise during response activities.

Expected Outcome

  • The incident is identified and contained quickly.
  • Operational disruption and data exposure are minimized.
  • Evidence is preserved for investigation and decision-making.
  • Recovery actions restore operational control and reduce repeat risk.