Security Information and Event Management (SIEM)

What Is Security Information and Event Management?

Security Information and Event Management (SIEM) collects and consolidates log and event data to help Security Operations Centers (SOCs) proactively recognize and remediate potential threats and vulnerabilities. A SIEM solution combines Security Information Management (SIM) and Security Event Management (SEM) into a single, unified platform that collects security logs and monitors network activity in real-time. Initially taking the form of simple data management and security alerting systems, SIEM solutions have since evolved to incorporate functionality like User and Entity Behavior Analytics (UEBA) and more advanced data orchestration. 

SIEM provides the necessary insight and information to better identify, track, and respond to security incidents. 

Benefits of SIEM

The key benefits of SIEM include the following: 

  • Real-time threat detection across an organization’s entire network infrastructure
  • Significantly improved mean time to detect and mean time to respond to security incidents and events
  • Streamlined regulatory compliance thanks to centralized auditing and reporting
  • A single, unified view of security data, including potential threats.
  • Access to advanced threat intelligence
  • Improved transparency in monitoring users, devices, and applications
  • Easier, more effective post-incident investigations

How SIEM Works

SIEM solutions aggregate and analyze log and event data to identify possible threats that may escape the notice of human personnel. The data they collect is typically quite broad in scope and includes logs from systems, applications, devices, and security tools. SIEM tools are also configured to flag specific predefined threats, such as failed logins and possible malicious activity.

When a SIEM tool identifies a potential threat, it generates a security alert which is then forwarded to SOCs as a notification. These alerts are generally unsorted and uncategorized, although security teams can apply a predefined ruleset to support intelligent prioritization. For instance, a user who generates three failed login attempts followed by a successful one likely just forgot their password, while a user who generates 30 failed login attempts in as many minutes represents a possible brute force attack. 

SIEM Features and Capabilities

While some SIEM tools are more advanced than others, all include, at minimum, the following basic functionality.

Log Management

A SIEM solution collects event data from across an organization’s network, storing and analyzing that information in real time. The scope of this data is typically quite broad and includes information generated by users, applications, physical assets, virtual assets, cloud environments, security tools, and network assets. A SIEM solution typically also categorizes and stores this data for compliance purposes. 

Some SIEM platforms may also incorporate external threat data and third-party threat intelligence, though this functionality is typically reserved for Security Orchestration, Automation, and Response (SOAR) tools. 

Event Correlation

Event correlation is where the analysis portion of SIEM comes into the picture. As it collects event data, a SIEM solution will identify patterns in that data that may indicate the presence of a potential threat. The application of UEBA and cybersecurity AI to SIEM further augments this capability, allowing the SIEM tool to create a baseline for each user and system on an organization’s network and flag any deviations from this baseline as potentially suspicious. 

Incident Monitoring

A SIEM platform doesn’t just passively collect log and event data. It actively monitors each internal asset in real time. Not only does this provide security teams with greatly improved network visibility, but it also allows for more effective monitoring and management of developing incidents and threats. 

Security Alerts

When a SIEM solution detects a potential threat, it generates a notification to inform the organization’s security team. Out of the box, there is little differentiation between alerts in terms of severity and priority. IT personnel may need to apply additional rules to reduce the chances of notification fatigue. 

Compliance Management and Reporting

How SIEM consolidates and stores event data makes it well-suited to support an organization’s compliance efforts. Most SIEM platforms are capable of generating real-time compliance reports for multiple standards, including GDPR, HIPAA, SOX, and PCI-DSS. They can also be preconfigured to detect and alert potential compliance violations and threats. 

Extended Detection and Response (XDR) has much in common with SIEM on the surface, as both collect, aggregate, and analyze data from multiple sources. However, XDR is considerably more advanced than SIEM. A SIEM tool cannot, for instance, automatically orchestrate a real-time response to a cyber threat across multiple endpoints and environments, nor can it make proactive adjustments to network defenses to neutralize threats. 

Even the most advanced SIEM tools primarily exist as a means of detection and prioritization, not remediation. 

XDR has a slightly different focus from SIEM and should not be treated as a complete replacement. While SIEM focuses on log and event management, XDR is more concerned with endpoint security and threat intelligence. The two work quite well in tandem with one another, as a SIEM solution can provide an additional threat intelligence feed from which an XDR platform can draw. 

As with XDR, SOAR has a considerably more expansive scope than SIEM. It pulls information not just from internal sources but also from third-party threat intelligence and external tools. It also provides intelligent alert prioritization and predefined investigation paths for an organization’s SOC. Again, as with XDR, the differences here are largely complementary. 

SOAR is by no means superior to SIEM, as the two serve different purposes. A SIEM tool provides intelligent alerts about potential incidents, while a SOAR platform can further prioritize and manage those alerts. 

Ultimately, a complete approach to cybersecurity incident and event management will incorporate SIEM, SOAR, and XDR as parts of a cohesive whole rather than as opposing solutions. 


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