Enhancing Microsoft Sentinel: Part 1 – Building a Stronger Foundation
In the ever-evolving landscape of cybersecurity, staying ahead of threats is paramount. Microsoft Sentinel, a powerful cloud-native SIEM (Security Information and Event Management) solution, empowers Information Security Architects and Engineers to do just that. In this three-part series, we will explore how to make significant improvements to Microsoft Sentinel to bolster your organization’s security posture. Today, in Part 1, “Building a Strong Foundation,” focuses on the critical initial steps.
When a security team is engaged, I often hear about how the load of incidents and alerts is ever-increasing. In my own experience, one of the most stressful things is the constant alerts, pings, beeps, and “important” issues flooding into the queue. There is always something that is important to someone, so many of the alerts need to be reviewed with some critical thinking, or human intervention….or do we really need all the alerts coming in?
The answer, of course, varies greatly in each environment; but if you review your last 30 days of incidents and alerts in Sentinel and find that even a few each hour or day can be handled differently using some automation, then it’s time to review your configurations and take action!
Part 1: Building a Stronger Foundation
Assess Your Current Setup:
Before embarking on enhancements, take stock of your current Sentinel configuration. Dive deep into your Azure and M365 environments.
Analyze the existing:
- data sources,
- detection rules, and
- incident workflows.
Identify gaps and areas that need improvement. Your in-depth knowledge of Azure and M365, gained through your direct insights of your own environments will be invaluable in conducting this assessment.
Remember to include review on any logs that are being forwarded or imported from other environments such as on-premises or other clouds.
Data Enrichment Strategies:
Enhancing data enrichment is pivotal. Leverage your expertise in Azure to fine-tune data collection and enrichment processes. Incorporate additional threat intelligence feeds, custom parsers, and connectors to extract more context from security events.
Using your familiarity with data sources and their nuances will aid in improving alert quality. I am a big believer in having meaningful alerts that drive human review. Whenever possible it’s best to deploy automated investigations, IP address lookups, and any other helpful automations for your environments, to reduce the load on your humans working your SOC (Security operations center). This helps improve response times, and let’s automation do some of the tedious and repetitive work.
Custom Alert Rules:
Sentinel’s flexibility is a strength.
Create custom alert rules that are finely tuned to your organization’s specific needs. Your role here is to craft rules that align with your security policies. This proactive approach not only helps in reducing false positives but also ensures that critical threats are not overlooked. Remember to keep alerts meaningful so that automation rules, and Analytics rules are only raising incidents that SOC members need to interact with.
Automation with Playbooks:
Automation is a key theme in modern security operations. Design playbooks that automate repetitive tasks and response actions. Your proficiency in Azure and Microsoft Defender security products makes you well-suited to implement playbooks effectively. Integrate with Azure Logic Apps or other automation tools to streamline incident response workflows.
Log Retention and Compliance:
Consider log retention and compliance requirements. Your knowledge of your organization’s data retention requirements will help to empower you to design data retention policies that meet regulatory standards and security requirements.
Ensure that you are retaining the right data for the required duration, striking a balance between security needs and compliance obligations. Not every record needs to be kept for 7 or 10 years.
Today, in Part 1, we’ve covered the critical initial steps to enhance Microsoft Sentinel, including assessing your current setup, improving data enrichment, creating custom alert rules, implementing automation through playbooks, and addressing log retention and compliance considerations. These foundational steps lay the groundwork for a robust security monitoring system.
Good governance with Sentinel includes reviewing these settings on a cyclical basis to ensure that the configuration of data sources, Analytics rules, and other components are all aligned with your current needs. Business needs change over time, so come up with a plan to help stay in sync with the business.
In Part 2, we will delve into advanced customization and threat hunting techniques, where we’ll explore more intricate aspects of enhancing Microsoft Sentinel. Stay tuned for deeper insights into maximizing the potential of this powerful security solution.