Audit Log Review & Monitoring Playbook

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.

Important: Audit logs are only valuable if they are actively reviewed and monitored. Collecting logs without a structured review process creates blind spots in security and compliance.

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

01

Define Monitoring Scope

Identify which systems, users, and activities must be monitored based on risk, compliance, and operational requirements.

02

Access Audit Logs

Collect logs from Microsoft 365 audit sources including Entra ID, Exchange, SharePoint, Teams, and security alerts.

03

Filter And Analyze Activity

Search logs for relevant events such as sign-ins, permission changes, data access, and administrative actions.

04

Identify Anomalies

Look for abnormal patterns such as unusual locations, elevated privileges, or unexpected data access behavior.

05

Investigate Findings

Correlate log activity across services to understand the full scope and impact of suspicious activity.

06

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
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