What Is Security Information and Event Management (SIEM)?

Originally designed as a tool to assist organizations with compliance and industry-specific regulations, security information and event management (SIEM) is a technology that has been around for almost two decades. It combines security information management (SIM) with security event management (SEM) and provides the foundation for cyberthreat detection capabilities.

Security Information and Event Management (SIEM) Explained

SIEM technology helps to manage security incidents by collecting and analyzing log data, security events, and other events or data sources. Security operations center (SOC) analysts use SIEM tools to manage security incidents and detect and respond to potential threats quickly.

According to Gartner, businesses looking for SIEM today need a solution to collect security event logs and telemetry in real time for threat detection, incident response, and compliance use cases.

They also need the ability to analyze the telemetry to detect attacks and other flagged activities. Along with SIEM comes the ability to investigate incidents, report on activities, and store the relevant events and logs.

SIEM solutions play a crucial role in helping security teams enhance their cybersecurity efforts.

Explore how SIEM solutions intertwine with SOC teams to easily aggregate data and identify potential issues by reading our article, What is a SIEM Solution?

How Does SIEM work?

SIEM works by collecting security-related data from various sources within an organization's network, such as logs from firewalls, IDS, servers, and applications. This data is aggregated into a central repository, where it undergoes correlation analysis to identify patterns, anomalies, and potential security incidents.

SIEM generates alerts for these incidents, allowing security analysts to investigate and respond. It also provides reporting capabilities for compliance requirements and integrates with external threat intelligence sources to enhance its detection capabilities.

SIEM operates in real time, continuously monitoring the network, adapting and learning from new patterns to improve its detection accuracy over time.

Discover how SIEM software can help your organization manage security-related data by reading, What is Security Information and Event Management Software?

How Are SIEM Solutions Deployed?

SIEM solutions can be deployed differently, depending on an organization’s requirements and resources. Here are some of the most common deployment options:

• On-premises deployment: In this approach, the SIEM solution is deployed within the organization's own infrastructure. It typically involves setting up dedicated hardware or virtual machines to host the SIEM software. The organization has full control over the infrastructure, data storage, and maintenance, but it requires the necessary hardware, software licenses, and expertise to manage and operate the SIEM system.
• Cloud-based deployment: SIEM solutions can be deployed in the cloud, utilizing infrastructure as a service (IaaS) or software-as-a-service models. With a cloud-based deployment, the organization leverages a provider's infrastructure, eliminating the need for on-premises hardware and reducing maintenance overhead. The SIEM vendor takes care of hardware provisioning, software updates, and scalability, while the organization focuses on configuring and managing the SIEM platform.
• Hybrid deployment: Organizations can adopt a hybrid approach that combines on-premises and cloud-based deployments. They may choose to keep certain sensitive data or critical systems on-premises while utilizing the cloud for scalability or specific use cases. This approach offers flexibility and allows organizations to tailor their SIEM deployment to their unique requirements.
• Managed security service providers (MSSPs): Some organizations prefer to outsource their SIEM deployment and management to MSSPs. MSSPs provide expertise in deploying, configuring, and maintaining SIEM solutions. They monitor and manage the SIEM infrastructure, analyze security events, and provide actionable insights to the organization's security team. This option is suitable for organizations with limited resources or those seeking external expertise to enhance their security operations.

When deploying SIEM solutions, organizations should consider factors such as their IT infrastructure, data sensitivity, regulatory compliance requirements, scalability needs, budget, and available expertise. It's crucial to assess the benefits and trade-offs of each deployment option to determine the most suitable approach for their specific circumstances.

Learn how SIEM tools and services offer a holistic view of your organization's information security in our article, What are Security Information and Event Management Tools?

SIEM Capabilities

A SIEM’s main functionality is to aggregate loads of data and consolidate it into one system for searchability and reporting purposes. The key capabilities SIEM provides that are most useful to enterprises include:

• Ingesting data for monitoring, alerting, investigation, and ad hoc searching
• User and entity behavior analytics (UEBA) to detect abnormal behavior or suspicious activities related to users, entities, or applications. UEBA analyzes patterns and deviations from normal behavior to identify insider threats or compromised accounts.
• Collect and aggregate logs from diverse sources, such as network devices, servers, endpoints, applications, and security tools for centralized storage and analysis of security-related data.
• Log analysis and forensics capabilities allow security teams to investigate and analyze security incidents. They provide historical log data, search functionalities, and visualization tools to understand the attack timeline, affected systems, and potential root causes.
• Continuously monitor events in real time, analyzing logs and applying predefined rules and correlation techniques to provide immediate alerts and notifications for potential security incidents or anomalies.
• Identify patterns, anomalies, and potential security threats by utilizing advanced analytics, machine learning, and behavioral analysis. By correlating events from multiple sources and incorporating threat intelligence, SIEM systems enhance the detection of sophisticated attacks.
• Searching and reporting from data for advanced breach analysis
• Provide workflows and automation capabilities to facilitate incident response and enable security teams to track and manage incidents, assign tasks, and collaborate effectively during the incident resolution process.
• Integrate with various security tools, such as firewalls, intrusion detection systems (IDS), and vulnerability scanners, to gather additional contextual information and enrich security event analysis. Integration with orchestration platforms enables automated response and remediation actions.
• Meet compliance requirements by collecting and storing logs in a centralized repository and providing predefined compliance rules, generating reports, and assisting with audits.
• Visualize and communicate security insights effectively through customizable dashboards and reporting features offering metrics, trends, and executive summaries to demonstrate the security posture and support decision-making.
• Store historical log data for the long term both to help with compliance but to enable the correlation of data over time to assist security analysts with forensics and investigations in the event of a data breach.

These capabilities collectively empower security teams to detect, respond to, and mitigate security incidents efficiently, enabling organizations to proactively safeguard their digital assets and infrastructure.

XDR Vs. SIEM

XDR offers a modern integrated approach to threat detection and response, covering a wider range of data sources and providing real-time capabilities. SIEM is more focused on log and event management, historical analysis, and compliance reporting. Organizations should consider their specific security needs and existing infrastructure when choosing between the two. Many organizations use a combination of both XDR and SIEM for comprehensive security monitoring and incident response.

Deep dive into how XDR (extended detection and response) and SIEM (security information and event management) differ in their approach and scope by reading, What is the Difference Between SIEM vs. XDR?

Limitations of SIEM

While SIEM solutions offer valuable capabilities, they also have certain limitations that organizations should be aware of:

1. Complexity and deployment challenges: SIEM implementations can be complex and require careful planning, configuration, and ongoing maintenance. Organizations may face challenges in integrating SIEM with existing infrastructure, ensuring data compatibility, and fine-tuning the system for optimal performance.
2. False positives and noise: SIEM systems generate alerts based on predefined rules and correlations, which can result in false positives. False positives occur when the system triggers alerts for events that are not actually security incidents, leading to alert fatigue and wasting the security team's time and resources.
3. False negatives and advanced threats: SIEM solutions rely on predefined rules and signatures to detect security threats. However, sophisticated attacks and advanced persistent threats (APTs) may bypass these rules and go undetected. SIEMs may struggle to identify novel attack techniques or zero-day exploits without timely updates or advanced analytics.
4. Skill and resource requirements: Effective implementation and operation of SIEM systems require skilled personnel with expertise in security operations, log analysis, and incident response. Organizations may face challenges in finding and retaining qualified staff to manage and operate the SIEM solution effectively.
5. Scalability and performance: Collecting, storing, and analyzing large amounts of data can strain the system's resources, impacting real-time monitoring, event correlation, and response times.
6. Data source coverage and integration: SIEM solutions depend on the availability and compatibility of log data from various sources. Integrating new data sources, such as cloud platforms or IoT devices, may require additional configuration or custom development. Incomplete data source coverage can result in blind spots and limited visibility into potential security threats.
7. Maintenance and updates: SIEM systems require regular updates to keep up with evolving security threats, compliance regulations, and software patches. Maintaining the SIEM infrastructure, applying updates, and managing vendor relationships can be time-consuming and resource-intensive.
8. Cost: SIEM solutions can involve significant upfront and ongoing costs, including licensing fees, hardware or cloud infrastructure, personnel training, and maintenance. Small and mid-sized organizations may find it challenging to justify the cost and resource investment required for a SIEM deployment.

Organizations should carefully evaluate their requirements, consider the limitations, and implement appropriate measures to mitigate potential challenges. Augmenting SIEM with other security technologies and practices can help address some of these limitations and provide a more comprehensive defense posture.

The Future of SIEM

Stopping today’s threats requires a radically new approach to security operations. The future of SIEM is likely to be shaped by several key trends and advancements in the field of cybersecurity, such as the following:

• Integration with artificial intelligence and machine learning
• Cloud-native and hybrid deployments
• User and entity behavior analytics (UEBA)
• Threat intelligence integration
• Automation and orchestration
• Enhanced user experience and visualization
• Compliance and privacy management
• Integration with extended detection and response (XDR)

It's important to note that the future of SIEM will be shaped by the evolving threat landscape, technology advancements, and the specific needs of organizations. As cybersecurity continues to evolve, SIEM solutions will adapt and evolve to meet the challenges of detecting, mitigating, and responding to emerging threats effectively.

The Cortex family of products – including Cortex XSIAM, Cortex XDR, Cortex XSOAR, and Cortex Xpanse – offers AI-driven, scalable, and comprehensive security for the SOC of the future.

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