Deploying SIEM on Azure: Pros and Cons of Microsoft Sentinel

What Are the Options for Deploying a SIEM in the Azure Cloud?

When considering deploying a Security Information and Event Management (SIEM) system in the Azure cloud, organizations can choose from a variety of models that suit their specific security and operational needs: 

• Microsoft Sentinel is a fully managed, cloud-native SIEM solution provided by Microsoft. This platform integrates seamlessly with Azure and other Microsoft services, offering out-of-the-box security solutions and streamlined data management. 
• Third-party SIEM solutions can also be used on Azure. These systems can be hosted on Azure virtual machines, or deployed via the Azure Marketplace (see a full selection of SIEM options here), allowing businesses to leverage Azure’s global infrastructure while utilizing the SIEM product of their choice.

In the remainder of this article, we’ll focus on Azure’s first-party offering, Microsoft Sentinel.

What Is Microsoft Sentinel (Formerly Azure Sentinel)?

Microsoft Sentinel, formerly known as Azure Sentinel, is Microsoft’s cloud-native Security Information and Event Management solution. It provides comprehensive security analytics across a user’s enterprise. It leverages artificial intelligence, enabling security professionals to detect, prevent, and respond to threats quickly across their distributed networks.

Microsoft Sentinel offers a scalable, cloud-based platform that integrates with various Microsoft and third-party services. This integration enhances the visibility of security data and alerts, making it easier for organizations to manage their security posture.

In April, 2024, Microsoft announced it would combine Microsoft Sentinel and Microsoft Defender XDR into its new Unified Security Operations Platform.

Tips from the expert

Steve Moore is Vice President and Chief Security Strategist at Exabeam, helping drive solutions for threat detection and advising customers on security programs and breach response. He is the host of the “The New CISO Podcast,” a Forbes Tech Council member, and Co-founder of TEN18 at Exabeam.

In my experience, here are tips to optimize deploying a SIEM in Azure Cloud or using Microsoft Sentinel effectively:

Optimize rule sets with baseline tuning
Sentinel’s analytics rules can generate excessive alerts if not configured correctly. Begin with baseline rules, monitor alert volumes, and iteratively refine them to align with your threat landscape.

Start with a hybrid deployment for phased integration
If you have on-premises systems, start with a hybrid SIEM model. Integrate cloud and on-premises logs to ensure comprehensive visibility while gradually adapting to Azure’s ecosystem.

Leverage Azure’s native monitoring tools for cost control
Use tools like Azure Monitor and Cost Management to track data ingestion rates and predict Sentinel costs. Configure data volume caps to prevent unexpected budget overruns.

Enhance data ingestion with tiered log management
Use Log Analytics workspaces with tiered storage to balance performance and cost. Store high-priority logs in hot storage for real-time analysis and archive less-critical logs for compliance needs.

Combine Microsoft and third-party threat intelligence
While Sentinel provides built-in threat intelligence, integrate third-party feeds through Threat Intelligence Platforms (TIPs) or custom parsers for a more diverse view of emerging threats.

Key Features and Capabilities of Microsoft Sentinel 

Here are some of the main features and capabilities of Sentinel.

1. Data Connectors

Data connectors serve as the bridge between the Sentinel platform and various data sources. These connectors enable organizations to import security data from Microsoft products, cloud environments, and third-party services. The integration accelerates the process of recognizing and responding to security threats.

The extensive selection of data connectors in Microsoft Sentinel enables collection of logs and data from across their digital environment. This data collection is useful for deep security analysis and the early detection of potential threats.

2. Workbooks

Workbooks provide customizable dashboards for visualizing and analyzing security data. They can be tailored to meet organizational needs, offering insights into security trends and anomalies. Workbooks enable security teams to monitor their environment’s health and security status efficiently.

By leveraging workbooks, organizations can drill down into detailed reports for in-depth analysis of security incidents and patterns. This capability enhances the decision-making process, allowing for proactive security management and strategic planning.

3. Log Retention

Microsoft Sentinel offers configurable log retention policies, enabling organizations to store security logs and data for a defined period. These policies ensure that crucial security information is retained long enough to comply with regulatory requirements and to facilitate thorough investigations when needed.

The flexibility in log retention policies helps organizations balance between operational needs and storage costs. It allows for the effective management of log data, ensuring that valuable security insights are preserved without unnecessarily increasing storage expenses.

4. Analytics

Analytics in Microsoft Sentinel use advanced algorithms and machine learning to identify threats and anomalies in real time. These analytics capabilities enable organizations to detect unusual activities and potential security breaches swiftly. The system continuously learns from the evolving threat landscape, improving its detection accuracy over time.

With the analytics feature, security teams can focus on validated threats, reducing the volume of false positives. This targeted approach streamlines the response process and enhances the overall efficiency of the security operations center (SOC).

5. Threat Hunting

Threat hunting empowers security analysts to proactively search for hidden threats within their digital environments. Utilizing custom queries and advanced hunting techniques, analysts can uncover suspicious activities that conventional security tools may overlook. 

Microsoft Sentinel provides a rich toolkit for threat hunting, including predefined templates and a query language. These resources enable analysts to efficiently search through vast amounts of security data, facilitating the early identification and mitigation of potential threats.

6. Threat Intelligence

Threat intelligence enriches the security analysis by integrating knowledge of current threats and vulnerabilities. This intelligence is derived from a range of sources, including Microsoft’s extensive security research, third-party feeds, and indicators of compromise (IoCs) shared by industry partners, adding context to detected anomalies.

Leveraging threat intelligence, organizations can enhance their security posture by being well-informed about the latest threats and attacker techniques. This knowledge enables targeted defenses and strengthens overall security measures.

How Microsoft Sentinel Works 

Here’s an overview of the Sentinel workflow.

Collection

Sentinel starts by gathering data from various sources, including logs, devices, users, applications, and network traffic. This data collection is facilitated by the extensive range of data connectors available in the platform. By aggregating data from disparate sources, Sentinel creates a unified data repository for analysis.

Detection

Next, Microsoft Sentinel utilizes the aggregated data to identify potential security threats. This is achieved through a combination of rule-based strategies and machine learning algorithms. The detection mechanisms are designed to recognize patterns indicative of malicious activity, from simple anomalies to complex, multi-stage attacks.

Investigation

The investigation phase involves analyzing detected threats to understand their nature, scope, and potential impact. This in-depth analysis enables security teams to determine the appropriate response actions. Microsoft Sentinel aids this process through automated investigation features and visual representation tools, streamlining the investigation of complex incidents.

Response

Microsoft Sentinel’s response mechanisms allow for the swift containment and remediation of threats. The platform offers automated response actions, such as isolating affected devices or blocking malicious IPs, which can be triggered based on predefined criteria. 

For incidents requiring manual intervention, Sentinel provides detailed incident reports and response recommendations. Organizations can customize their response strategies to align with their specific procedures and policies. 

Limitations of Microsoft Sentinel 

While Microsoft Sentinel is a powerful platform, there are some limitations to be aware of. These limitations were reported by users on the G2 platform.

Performance and Usability Issues

Microsoft Sentinel users have encountered challenges with data connectors not being visible on the platform, complicating the process of conducting health checks on these connectors. Alternative methods or workbooks allowing for manual monitoring of data connectors would be useful. There have also been reports of queries in Sentinel running slower than expected.

Non-Predictable Pricing

The pricing model can be difficult for organizations to predict, which can lead to budgeting challenges. Sentinel’s cost is based on the volume of data ingested and stored, so large amounts of security data may result in higher expenses than anticipated. This unpredictability is particularly challenging for organizations with fluctuating data volumes or those trying to forecast costs for budgeting purposes.

UI Complexity

Users sometimes report that Sentinel’s user interface is complex and not as intuitive as desired, especially for new users or those with limited technical expertise. The platform’s comprehensive features and functionalities can overwhelm users unfamiliar with cloud-native SIEM solutions. 

Customization and Configuration Challenges

Adapting Microsoft Sentinel to meet specific organizational requirements can be a complex and time-consuming task. While this customization is required for tailoring the tool to different security environments, it can also slow down the deployment process. The need for a certain level of technical knowledge to configure Sentinel may pose a risk, particularly for organizations lacking a dedicated cybersecurity team.

Integration Difficulties

The integration methods offered by Sentinel may not be supported by third-party applications, especially older ones. This often leads to continuous support requests to third-party vendors. Additionally, compared to other SIEM solutions, Sentinel struggles with efficiently parsing logs from syslog sources. It does not integrate smoothly with some non-Microsoft products.

Accessibility and Learning Curve

Sentinel can be challenging to navigate for individuals without a technical background. The platform requires users to write KQL (Kusto Query Language) scripts for custom reporting and log analysis, which introduces a steep learning curve, especially for those new to the platform. This complexity may hinder the adoption and effective use of Sentinel.

Exabeam Fusion SIEM: The Ultimate Microsoft Sentinel Alternative

Exabeam Fusion SIEM is a cloud-delivered solution that combines SIEM with the world-class threat detection, investigation, and response (TDIR) of Extended Detection and Response (XDR). 

With powerful behavioral analytics built into Fusion SIEM, analysts can detect threats missed by other tools. Prescriptive workflows and pre-packaged content enable successful SOC outcomes and response automation. Fusion SIEM also provides the cloud-based log storage, rapid and guided search, and comprehensive compliance reporting expected of any modern SIEM.

With Fusion SIEM you can:

• Use threat detection events, investigation, and response from multiple tools
• Collect, search, and enhance data from anywhere
• Detect threats missed by other tools through behavioral analytics
• Achieve successful outcomes with prescriptive, threat-centric use case packages
• Enhance productivity and reduce response times with automation
• Meet regulatory compliance and audit requirements with ease

How Exabeam Fusion Works

Data from anywhere enhances visibility  – Visibility is the first pillar of security operations, but it is a challenge to achieve as modern organizations are making data available everywhere. Inefficient and overly complex traditional logging tools often require knowledge of proprietary query language, and are slow to deliver results. The continuous spread of data, infrastructure, and applications requires a new level of analytics for full visibility. Fusion SIEM collects data from the endpoint to the cloud, eliminating blindspots to give analysts a full picture of their environment. Rapid, guided search boosts productivity, and ensures analysts of all levels can access valuable data exactly when they need it.

Prescriptive TDIR use case packages and automation – It has become too complicated to build an effective SOC using legacy SIEMs and a selection of purpose-built security products. Every SOC is unique, with its own mix of tools, level of staffing and maturity, and processes and there is no standard way to tackle cybersecurity. Fusion SIEM solves this by leveraging prescriptive, threat-centered TDIR Use Case Packages that provide repeatable workflows and prepackaged content that spans the entire TDIR lifecycle. These use cases include all the content necessary to operationalize that use case, including: prescribed data sources, parsers, detection rules and models, investigation and response checklists, and automated playbooks.

Meet regulatory compliance and audit requirements  – Organizations must adhere to compliance regulations. Creating and maintaining compliance reports is time consuming but necessary. Whether you’re subject to GDPR, PCI, HIPAA, NYDFS, NERC, or utilizing a framework such as NIST or directives from DISA or CISA, Fusion SIEM significantly reduces the operational overhead of compliance monitoring and reporting. Fusion SIEM’s pre-packaged reports provide huge time savings spent correlating information, solves the risk of missing vital data, and eliminates the need to manually create compliance reports through report builder tools.