What is SIEM
Security information and event management (SIEM) evolved from two distinct technologies: SIM (Security Information Management) and SEM (Security Event Management). SIM tools were primarily centralized repositories for collecting, storing, and analyzing security-related data.
On the other hand, SEM tools were designed to provide real-time monitoring and analysis of security events. SIEM solutions provide real-time security monitoring, allowing teams to track and analyze events and maintain security data logs for auditing and compliance purposes.
How SIEM works
SIEM collects, analyzes, and correlates log data from various sources across an organization's IT infrastructure, such as firewalls, endpoints, servers, and applications. It uses predefined algorithms to detect anomalies, suspicious activities, or potential security threats.
When a threat is identified, the SIEM generates alerts, prioritizes them based on severity, and automates responses. This enables security teams to investigate and mitigate risks quickly while maintaining compliance and improving overall cybersecurity posture. Below are some processes of a SIEM.
Log collection
The first step is to collect relevant security data from various sources. The sources can include network devices, computers, servers, operating systems, applications, containers, and cloud services. They generate event logs with varying levels of severity. These logs are valuable for security monitoring, and troubleshooting system issues.
SIEM data collection can be accomplished using SIEM agents, which run on various endpoints to collect and forward log data to the SIEM solution. Alternatively, many SIEM solutions offer integrations that collect logs directly, eliminating the need for agents.
Logs collected from various sources often come in different formats. The next step involves normalizing and parsing these logs to convert them into a consistent, structured format for analysis.
Log normalization and parsing
Log normalization involves converting logs from various sources (e.g., firewalls, servers, applications) into a common, standardized format. This is essential because logs can have different structures, and normalization ensures consistency for SIEM analysis.
Following normalization, data parsing extracts key information from the logs by breaking down entries into components like timestamps, IP addresses, and event types, and organizing them in a structured format.
Log correlation and analysis
Log correlation and analysis involve linking related log data from different sources to identify patterns, trends, or anomalies that may indicate security threats or system issues. By analyzing correlated data, the SIEM can detect threats that may not be obvious in individual logs. For instance, if there’s a sudden spike in database access requests alongside an unexpected login from an unfamiliar location, the platform might correlate these events and flag them as suspicious.
Log correlation and analysis help identify several incidents quickly and provide better insights into security events, making it easier to investigate and understand incidents.
SIEM features
SIEM features include real-time alerting, threat visualization through intuitive dashboards, and compliance management. These features enable organizations to detect anomalies, correlate security events, ensure compliance, and respond to incidents.
Real-time threat detection and incident response
SIEM platforms continually analyze events from multiple log sources, when a potential security threat is detected, the platform generates security alerts to notify the security team. These alerts are prioritized based on the severity and potential impact of the threat. Security teams can then investigate these alerts, taking appropriate actions to mitigate risks.
Additionally, when integrated with complementary security tools such as XDR or SOAR, a SIEM solution can leverage these tools to automate incident responses. This includes isolating compromised hosts, blocking malicious IP addresses, or triggering predefined workflows for investigation and remediation.
Event visualization across an IT infrastructure
SIEMs collect data from various sources in an IT infrastructure. It uses dashboards to allow organizations to transform complex data into intuitive, graphical representations, enabling easier identification of anomalies, trends, and potential threats. For instance, a SIEM dashboard might display a spike in failed login attempts from multiple IPs, visualized on a heatmap. This type of visualization allows security analysts to quickly identify and block a brute-force attack in progress. Thereby enhancing threat detection, investigation, and response efficiency.
Compliance management and reporting
Organizations rely on SIEM solutions for compliance and reporting purposes. These solutions generate detailed reports that adhere to regulatory standards like GDPR, HIPAA, NIST, and PCI DSS.
This feature is essential for demonstrating compliance with data protection regulations, reducing the risk of fines and reputational harm. For instance, the SIEM solution monitors and logs card transaction activities, detects any unauthorized access attempts, and generates comprehensive reports to demonstrate compliance with PCI DSS.
Benefits of using a SIEM
SIEM solutions are essential for organizations facing numerous security threats. These solutions help security teams manage the large volume of daily alerts by efficiently triaging them and providing context for the investigation. SIEM solutions speed up threat detection and incident response by consolidating logs and analyzing security events.
Initially used by large enterprises for compliance purposes, SIEM technologies have evolved into crucial tools for detecting cyber threats. They are now widely adopted by organizations of all sizes to enhance their security posture and ensure quick and automated detection of security incidents. With the ongoing cybersecurity skills shortage and the ever-increasing threat landscape, SIEM solutions have become even more necessary in maintaining resilient security defenses.
Best practices for SIEM implementation
SIEM can significantly enhance security when properly deployed by providing better visibility and faster threat detection. To maximize its effectiveness, follow these best practices.
- Define clear objectives: Establish specific goals for your SIEM deployment, such as threat detection, compliance, or incident response, to align it with your organization's security needs.
- Maintain an asset inventory: Create and regularly update an inventory of all assets (devices, applications, and users) to ensure the SIEM monitors all critical components of your environment.
- Fine-tune correlation rules: Customize correlation rules to reduce false positives and focus on detecting genuine threats.
- Prioritize alerts: Classify alerts based on severity and potential impact to help security teams focus on the most critical incidents first.
- Integrate with other tools: Combine SIEM with complementary security solutions like SOAR, XDR, or firewalls for a more robust defense strategy.
- Training and user awareness: Ensure your security team is well-trained to use the SIEM tool effectively, interpret alerts, and respond to incidents. Additionally, educate all users on cybersecurity best practices, such as identifying and avoiding phishing links, to reduce the risk of human error leading to security breaches.
- Automation: Use automated response capabilities to quickly contain and mitigate threats, reducing manual intervention and response time.
- Regular updates and patching: Keep your SIEM solution updated with the latest threat intelligence feeds, patches, and rule sets to ensure it remains effective against evolving threats.
By following these best practices, you can enhance the efficiency and effectiveness of your SIEM solution, improving your overall cybersecurity posture.
Wazuh combines SIEM and XDR capabilities to protect on-premises endpoints and cloud workloads. Learn more about the Wazuh in our documentation.
