What Is SIEM, Why Is It Important and 13 Key Capabilities

Comparing SIEM vs. Other Cybersecurity Solutions

UEBA vs. SIEM

User and entity behavior analytics (UEBA) and security information and event management (SIEM) are complementary tools in modern cybersecurity. Most modern SIEM solutions include UEBA technology.

Focus on Behavior vs. Events:
UEBA specializes in monitoring and analyzing user and entity behavior to detect anomalies that might indicate insider threats, account compromise, or targeted attacks. It builds profiles over time and flags deviations from normal behavior. SIEM focuses on event data, collecting logs from various systems, correlating them, and applying rules to identify security incidents.

Detection Without Rules:
Traditional SIEM systems rely heavily on predefined rules and correlation logic. UEBA, however, uses machine learning and advanced analytics to detect threats without needing specific rules or known attack signatures. This makes UEBA particularly effective against novel or sophisticated attacks that evade traditional SIEM detection.

Complementary Use:
Modern SIEMs often incorporate UEBA functionality as part of their capabilities. UEBA enhances SIEM by providing insights into behavioral anomalies, while SIEM provides the infrastructure for log management, data correlation, and incident response. Together, they offer a holistic approach to threat detection and response.

SIEM vs. SOAR

Security information and event management (SIEM) and security orchestration and automation response (SOAR) serve distinct roles in cybersecurity, though many modern SIEM solutions include SOAR technology.

Data Aggregation vs. Automation:
SIEM systems are primarily designed for collecting, storing, and analyzing security data from across the organization. Their main purpose is to detect threats and provide alerts. SOAR, in contrast, focuses on automating and orchestrating responses to incidents, streamlining workflows, and reducing the time to contain and mitigate threats.

Incident Response:
While SIEM alerts analysts about potential security events, SOAR takes it further by executing automated playbooks to respond to incidents. For example, upon detecting a malware infection via the SIEM, a SOAR system might automatically isolate the infected system, notify stakeholders, and update firewall rules.

Integration:
SOAR platforms are designed to integrate with SIEMs and other security tools. They use SIEM data as an input, enriching it with threat intelligence and automating response actions. This integration enables organizations to scale their security operations, reducing the reliance on manual processes.

SIEM vs. XDR

Security information and event management (SIEM) and extended detection and response (XDR) are both solutions for threat detection and response, but they differ in scope and architecture.

Breadth vs. Depth:
SIEM systems are designed to aggregate and correlate data from a wide range of sources across the organization, such as servers, firewalls, and endpoints. XDR, on the other hand, focuses on integrating and optimizing detection and response capabilities across specific environments, like endpoints, networks, and cloud workloads.

Data Correlation:
SIEM relies on rules, correlation logic, and machine learning to detect security events. XDR goes a step further by natively integrating data from a vendor’s suite of security tools, enabling deeper context and more precise detection. This native integration reduces the complexity of managing multiple tools and ensures better visibility across key attack surfaces.

Operational Complexity:
Traditional SIEM systems often require significant configuration and tuning to be effective. XDR, being vendor-specific, typically offers faster deployment and simplified operations, but it may lack the flexibility to incorporate third-party tools or custom data sources that SIEM can handle.

SIEM Use Cases

Security monitoring

SIEMs help with real-time monitoring of organizational systems for security incidents. A SIEM provides a unique perspective on security incidents because it has access to multiple data sources — for example, it can combine alerts from an intrusion detection system (IDS) with information from an antivirus (AV) product and authentication logs. It helps security teams identify security incidents that no individual security tool can see, and helps them focus on alerts from security tools that have special significance.

Advanced threat detection

SIEMs can help detect, mitigate, and prevent advanced threats, including:

• Malicious insiders – A SIEM can use browser forensics, network data, authentication, and other data to identify insiders planning or carrying out an attack.
• Data exfiltration (sensitive data illicitly transferred outside the organization) – A SIEM can pick up data transfers that are abnormal in their size, frequency, or payload.
• Outside entities, including advanced persistent threats (APTs) – A SIEM can detect early warning signals indicating that an outside entity is carrying out a focused attack or long-term campaign against the organization.

Forensics and incident response

SIEMs can help security analysts determine that a security incident is taking place, triage the event, and define immediate steps for escalation and remediation.

Even if an incident is known to security staff, it takes time to collect data to fully understand the attack and stop it — the SIEM can automatically collect this data and significantly reduce response time. When security staff discovers a historic breach or security incident that needs to be investigated, SIEMs provide rich forensic data to help uncover the kill chain, threat actors, and mitigation.

Compliance reporting and auditing

SIEMs can help organizations prove to auditors and regulators that they have the proper safeguards in place and that security incidents are known and contained.

Many early adopters of SIEMs used it for this purpose:  aggregating log data from across the organization and presenting it in audit-ready format. Modern SIEMs automatically provide the monitoring and reporting necessary to meet standards like HIPAA, PCI/DSS, SOX, FERPA, and HITECH.

SIEM Implementation Best Practices

Inventory Data Sources

Before implementing a SIEM solution, create a comprehensive inventory of data sources across your IT environment. Include all systems that generate logs, such as servers, endpoints, firewalls, routers, IDS/IPS systems, and cloud services. Don’t forget SaaS applications, databases, and specialized systems such as OT/IoT devices, which often generate valuable security data.

For each data source, identify what types of logs it produces (e.g., access logs, error logs, authentication attempts) and how they align with your security objectives. Ensure the data can be ingested via supported protocols such as syslog, SNMP, WMI, or APIs. Mapping out these sources not only ensures comprehensive coverage but also helps identify and eliminate blind spots, which attackers often exploit.

Plan for Scalability

A SIEM implementation needs to be future-proof, able to handle increasing volumes of log data and a growing number of integrated systems. Choose a platform that supports elastic storage, such as cloud-native data lakes or hybrid setups, so you can manage both current and future needs. Scalability planning is particularly critical for organizations with aggressive expansion plans or those operating in rapidly growing environments like cloud and IoT.

In addition to storage, consider the processing capacity of the SIEM. As log ingestion grows, ensure that the system can maintain real-time analysis and alerting without delays. Discuss scalability plans with the vendor to understand limitations and costs. Planning for scalability upfront reduces the likelihood of system slowdowns or costly upgrades as your organization evolves.

Deploy in Phases

Implementing a SIEM across an entire organization in one go can overwhelm both the security team and the system itself. Instead, adopt a phased approach to minimize risk and disruption. Begin by focusing on critical systems, such as those that house sensitive data, support business-critical processes, or face the highest risk of attack.

Test the SIEM with these systems, refining log collection, correlation, and alerting as you go. Use insights from the initial phase to improve processes before rolling out to additional systems. This iterative approach allows you to identify and resolve issues early, fine-tune configurations, and build confidence in the system’s effectiveness without overwhelming the security team.

Establish Roles and Processes

A SIEM is only as effective as the team operating it. Define roles and responsibilities within your security operations center (SOC) to ensure accountability and streamline workflows. Typical roles might include log management specialists, security analysts, incident responders, and compliance auditors. Assign clear ownership for activities like monitoring alerts, creating rules, and maintaining the system.

In addition, develop and document standard operating procedures (SOPs) for common tasks, such as triaging alerts, escalating incidents, and responding to specific threat scenarios. Regularly train your team on using the SIEM platform and analyzing its outputs. With well-established roles and processes, you can improve efficiency, reduce response times, and ensure a consistent approach to security.

Plan for Compliance

Compliance is a significant driver for many organizations adopting SIEM solutions. To make compliance easier, map regulatory requirements to SIEM capabilities, such as log collection, retention policies, and reporting. Identify which data sources are relevant to specific standards like PCI DSS, HIPAA, GDPR, or SOX, and configure the SIEM to gather and retain logs accordingly.

Automate the generation of compliance reports that highlight metrics such as access logs, failed login attempts, and policy violations. Schedule periodic reviews of the SIEM’s compliance settings to ensure they remain up-to-date with regulatory changes. Additionally, use the SIEM to track and document incident response activities, as these are often subject to audit requirements. Effective compliance planning not only simplifies audits but also helps demonstrate a proactive approach to regulatory obligations.

Exabeam Fusion SIEM

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