What This Playbook Covers
Audit logs provide critical visibility into user activity, system changes, and potential security threats. This playbook outlines how to review, monitor, and respond to audit log data within Microsoft 365 environments to detect risks, investigate incidents, and maintain operational control.
When This Playbook Is Used
Suspicious Activity Detection
Unexpected user behavior, unusual access patterns, or abnormal system activity is identified through alerts or review.
Incident Investigation
Audit logs are required to determine what occurred during a suspected security incident or breach.
Compliance And Audit Requirements
Logs are reviewed to meet regulatory, contractual, or security framework requirements.
Execution Steps
Define Monitoring Scope
Identify which systems, users, and activities must be monitored based on risk, compliance, and operational requirements.
Access Audit Logs
Collect logs from Microsoft 365 audit sources including Entra ID, Exchange, SharePoint, Teams, and security alerts.
Filter And Analyze Activity
Search logs for relevant events such as sign-ins, permission changes, data access, and administrative actions.
Identify Anomalies
Look for abnormal patterns such as unusual locations, elevated privileges, or unexpected data access behavior.
Investigate Findings
Correlate log activity across services to understand the full scope and impact of suspicious activity.
Document And Respond
Record findings, escalate as needed, and initiate incident response actions if security risks are confirmed.
Operational Requirements
Log Retention Policies
Ensure logs are retained for a sufficient period to support investigations and compliance requirements.
Defined Review Processes
Establish routine log review schedules and responsibilities to ensure continuous visibility.
Monitoring And Alerting Tools
Use automated tools and alerts to detect high-risk activity and reduce reliance on manual review.
Expected Outcome
- Critical system and user activity is visible across the environment
- Suspicious behavior is detected early and investigated quickly
- Audit evidence is available for compliance and incident response
- Monitoring processes improve overall security posture