Azure Sentinel Best Practices

This document outlines recommended practices for deploying, configuring, and managing Microsoft Azure Sentinel to maximize its effectiveness and efficiency.

Deployment and Configuration

1. Resource Organization

Organize your Azure Sentinel workspace within a dedicated Azure resource group and subscription to simplify management, access control, and billing.

Consider using separate workspaces for different environments (e.g., Dev, Test, Prod) or distinct security domains.
Leverage Azure Policy to enforce naming conventions and tagging for Sentinel resources.

2. Data Collection Strategy

Carefully plan which data sources to ingest into Azure Sentinel to balance security visibility with storage costs and performance. Prioritize data sources that provide critical security signals.

Enable specific logs for your chosen data connectors rather than ingesting all available logs.
Use log analytics agents for on-premises and multi-cloud resources efficiently.
Regularly review your data collection strategy to ensure it remains relevant and cost-effective.

3. Workspace Sizing and Performance

Choose an appropriate data retention period based on your compliance requirements and security needs. Optimize query performance by using efficient Kusto Query Language (KQL) queries.

Tip: Utilize Azure Sentinel's built-in performance optimization tools and regularly monitor query execution times.

Security Operations

4. Analytics Rules

Develop a comprehensive set of analytics rules that detect threats relevant to your organization. Leverage built-in rules and customize them to reduce false positives.

Start with out-of-the-box rules and then fine-tune them based on your environment.
Group similar detections to streamline investigations.
Use entities in your rules to enrich alerts with contextual information.

5. Incident Response with Playbooks

Automate incident response tasks using Azure Logic Apps (playbooks) to reduce manual effort and accelerate remediation.

Prioritize automating repetitive tasks such as blocking IPs, disabling users, or isolating machines.
Develop playbooks for common attack scenarios.
Test your playbooks thoroughly in a non-production environment.

Important: Ensure that playbooks have appropriate permissions and error handling to prevent unintended consequences.

6. Threat Hunting

Proactively hunt for threats that may have bypassed your automated detections. Develop hunting queries based on threat intelligence and known adversary tactics, techniques, and procedures (TTPs).

Use Azure Sentinel's built-in hunting queries as a starting point.
Collaborate with your security analysts to develop and refine hunting queries.
Regularly update your hunting queries based on new threat intelligence.

7. User and Entity Behavior Analytics (UEBA)

Enable and tune UEBA features to detect anomalous user and entity behavior that may indicate compromised accounts or insider threats.

Note: UEBA requires sufficient user sign-in data and other relevant logs for effective detection.

Governance and Management

8. Access Control

Implement the principle of least privilege for access to your Azure Sentinel workspace and associated resources. Use Azure Role-Based Access Control (RBAC) effectively.

Assign built-in roles where possible (e.g., Sentinel Reader, Sentinel Responder).
Create custom roles if specific permissions are required.
Regularly review user access and remove unnecessary permissions.

9. Monitoring and Auditing

Monitor the health and performance of your Azure Sentinel deployment. Audit changes made to configurations, rules, and playbooks.

Utilize Azure Monitor to track Sentinel's operational metrics.
Enable diagnostic settings for your Sentinel workspace to log operational data.

10. Continuous Improvement

Regularly review your Azure Sentinel implementation, threat landscape, and operational effectiveness. Adapt your strategies and configurations based on lessons learned and evolving threats.

Conduct periodic reviews of analytics rules, playbooks, and hunting queries.
Stay updated with new Azure Sentinel features and best practices from Microsoft.

By adhering to these best practices, you can build a robust and efficient Security Information and Event Management (SIEM) and Security Orchestration, Automation, and Response (SOAR) solution with Azure Sentinel.