1. Introduction
Elastic Security has rapidly become a cornerstone in the world of open-source cybersecurity solutions. As organizations face increasingly sophisticated threats, the need for robust, scalable, and cost-effective Security Information and Event Management (SIEM) platforms has never been greater. This article provides a comprehensive, step-by-step guide to building a free SIEM stack using Elastic Security, empowering security teams to detect, investigate, and respond to threats without the high costs associated with commercial SIEM products.
Whether you are a security analyst, IT administrator, or a cybersecurity enthusiast, this guide will walk you through the essentials of deploying and optimizing Elastic Security as a free SIEM solution, from installation to advanced threat detection.
2. Understanding SIEM and Elastic Security
2.1 What Is SIEM?
Security Information and Event Management (SIEM) is a technology that aggregates, analyzes, and correlates security data from across an organization’s IT infrastructure. SIEM platforms provide real-time visibility into security events, enabling organizations to detect threats, ensure compliance, and respond to incidents efficiently. According to CISA, SIEM is critical for effective threat detection and response in modern security operations centers (SOCs).
2.2 Overview of Elastic Security
Elastic Security is an open-source security solution built on the Elastic Stack (Elasticsearch, Logstash, Kibana, and Beats). It provides SIEM capabilities by collecting, storing, analyzing, and visualizing security data. Elastic Security offers features such as threat detection, investigation, and automated response, making it a powerful tool for organizations seeking a free SIEM stack. For more on Elastic Security’s capabilities, see the official Elastic Security documentation.
2.3 Why Choose a Free SIEM Stack?
Adopting a free SIEM stack like Elastic Security provides several advantages:
- Cost-effectiveness: No licensing fees for core features.
- Flexibility: Highly customizable and adaptable to diverse environments.
- Community Support: Backed by a large open-source community.
- Transparency: Open codebase for auditing and trust.
3. Prerequisites and System Requirements
3.1 Hardware and Software Requirements
Before deploying Elastic Security, ensure your system meets the following minimum requirements:
- CPU: Quad-core, 2.5 GHz or higher
- RAM: 16 GB (32 GB recommended for production)
- Storage: SSD with at least 100 GB free space (more for larger environments)
- Operating System: Linux (Ubuntu, CentOS, Debian), Windows Server, or macOS
- Java: OpenJDK 11+ (required for Logstash)
3.2 Supported Platforms
Elastic Stack components are cross-platform and support:
- Linux: Ubuntu, Debian, CentOS, Red Hat Enterprise Linux
- Windows: Windows 10/11, Windows Server 2016/2019/2022
- macOS: For development and testing
- Cloud: AWS, Azure, Google Cloud Platform
3.3 Preparing Your Environment
To ensure a smooth deployment:
- Update your operating system and install security patches.
- Configure network settings (firewall, ports 9200, 5601, 5044, etc.).
- Set up user permissions and create dedicated service accounts.
- Synchronize system clocks using NTP for accurate event correlation.
4. Deploying the Elastic Stack
4.1 Installing Elasticsearch
Elasticsearch is the core search and analytics engine of the Elastic Stack. To install:
# On Ubuntu/Debian
wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -
sudo apt-get install apt-transport-https
echo "deb https://artifacts.elastic.co/packages/8.x/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-8.x.list
sudo apt-get update && sudo apt-get install elasticsearch
sudo systemctl enable elasticsearch
sudo systemctl start elasticsearch
Refer to the official installation guide for other platforms.
4.2 Installing Kibana
Kibana provides the web interface for Elastic Security. To install:
sudo apt-get install kibana
sudo systemctl enable kibana
sudo systemctl start kibana
Access Kibana at http://localhost:5601 after installation. For advanced setup, see the Kibana installation guide.
4.3 Installing Logstash
Logstash is used for ingesting, parsing, and transforming data. To install:
sudo apt-get install logstash
sudo systemctl enable logstash
sudo systemctl start logstash
Logstash is highly configurable via pipelines. For more, see the Logstash documentation.
4.4 Setting Up Beats for Data Collection
Beats are lightweight agents for collecting and shipping data to Elasticsearch or Logstash. Common Beats include:
- Filebeat: For log files (system, application, security logs)
- Winlogbeat: For Windows Event Logs
- Packetbeat: For network traffic analysis
- Auditbeat: For audit framework data
sudo apt-get install filebeat
sudo systemctl enable filebeat
sudo systemctl start filebeat
Configuration guides for each Beat are available in the Beats documentation.
5. Configuring Elastic Security Features
5.1 Enabling the SIEM App in Kibana
After installation, access Kibana and enable the Security app (formerly known as the SIEM app):
- Log in to Kibana at http://localhost:5601
- Navigate to Security in the left sidebar
- Follow the setup prompts to initialize the SIEM features
5.2 Integrating Data Sources
Integrate diverse data sources for comprehensive visibility:
- Endpoints: Use Filebeat, Winlogbeat, or Auditbeat for endpoint logs
- Network: Use Packetbeat for network traffic
- Cloud: Integrate with AWS, Azure, or GCP logs
- Third-party: Use Logstash for custom log formats
5.3 Configuring Ingest Pipelines
Ingest pipelines allow you to parse, enrich, and transform incoming data before indexing. Example pipeline for parsing syslog:
PUT _ingest/pipeline/syslog_pipeline
{
"description": "Parse syslog messages",
"processors": [
{
"grok": {
"field": "message",
"patterns": ["%{SYSLOGBASE} %{GREEDYDATA:syslog_message}"]
}
}
]
}
Assign this pipeline to your Beat or Logstash configuration to normalize data. See Elasticsearch ingest pipelines for more.
6. Ingesting and Normalizing Security Data
6.1 Collecting Logs from Endpoints
Endpoint log collection is crucial for detecting threats. Use:
- Filebeat: For Linux/Unix system logs (e.g., /var/log/auth.log, /var/log/syslog)
- Winlogbeat: For Windows Security, Application, and System logs
- Auditbeat: For process, user, and file integrity monitoring
system
module).
6.2 Integrating Network Data
Network visibility is essential for detecting lateral movement and exfiltration. Use:
- Packetbeat: Monitors network protocols (DNS, HTTP, TLS, etc.)
- Zeek (formerly Bro): For advanced network analysis, integrated via Filebeat or Logstash
6.3 Parsing and Enriching Events
Normalize and enrich events for effective detection:
- Parsing: Use Logstash filters (grok, dissect) or ingest pipelines
- Enrichment: Add GeoIP, threat intelligence, or user context
- Field mapping: Align data with Elastic Common Schema (ECS) for consistency
7. Building Dashboards and Visualizations
7.1 Using Pre-built Security Dashboards
Elastic Security includes pre-built dashboards for common security use cases:
- Overview of alerts, events, and host activity
- Network traffic analysis
- User and entity behavior analytics
7.2 Creating Custom Visualizations
Build custom visualizations to tailor your SIEM stack:
- Use Kibana’s Lens and Visualize tools
- Create bar charts, line graphs, heatmaps, and maps
- Aggregate data by user, IP, event type, or time
7.3 Setting Up Alerts and Notifications
Configure alerts for real-time threat detection:
- Use Kibana’s Detection Rules (pre-built and custom)
- Set up Watchers for advanced alerting (requires basic license)
- Integrate with email, Slack, or webhooks for notifications
8. Use Cases: Detecting Threats with Elastic SIEM
8.1 Detecting Brute-force Attacks
Elastic SIEM can detect brute-force attacks by correlating failed login attempts:
- Monitor authentication logs for repeated failures from the same IP
- Use detection rules to alert on excessive failed logins
- Visualize attack patterns with Kibana dashboards
8.2 Monitoring Suspicious Network Activity
Identify suspicious network activity such as port scans or data exfiltration:
- Analyze Packetbeat or Zeek logs for unusual protocol usage
- Set up alerts for large outbound data transfers
- Correlate network events with endpoint activity
8.3 Investigating Security Incidents
Elastic SIEM supports incident investigation with timeline analysis:
- Pivot across logs, network, and endpoint data
- Use Kibana’s Timeline feature to reconstruct attack chains
- Document findings for compliance and reporting
9. Best Practices for Managing Your Free SIEM Stack
9.1 Performance Tuning
Optimize your Elastic Security stack for performance:
- Allocate sufficient heap memory to Elasticsearch and Logstash
- Use SSDs for data storage
- Implement index lifecycle management (ILM) for efficient data rollover
- Monitor cluster health with Kibana’s Stack Monitoring
9.2 Regular Updates and Maintenance
Stay secure and up-to-date:
- Apply security patches and version updates regularly
- Backup configuration and data indices
- Test updates in a staging environment before production rollout
9.3 Data Retention and Storage Optimization
Manage storage efficiently:
- Define data retention policies based on compliance needs
- Use index lifecycle policies to archive or delete old data
- Compress indices to save space
10. Limitations and Considerations of the Free Stack
10.1 Feature Gaps Compared to Paid Versions
While Elastic Security offers a powerful free SIEM stack, some features are exclusive to paid tiers:
- Advanced machine learning-based detection
- Automated response (SOAR) integrations
- Long-term support and enterprise-grade support
- Role-based access control (RBAC) enhancements
10.2 Scaling Challenges
Scaling a free SIEM stack can be challenging:
- Resource constraints on single-node deployments
- Complexity of managing multi-node clusters
- Potential performance bottlenecks with high log volumes
10.3 Community Support Resources
Free users rely on community support:
- Elastic Community Forums
- Elastic GitHub repositories
- Reddit: r/elastic
11. Conclusion
Building a free SIEM stack with Elastic Security empowers organizations to gain visibility, detect threats, and respond to incidents without significant financial investment. By leveraging the open-source Elastic Stack, security teams can customize their SIEM solution, integrate diverse data sources, and benefit from a vibrant community. While there are limitations compared to commercial offerings, Elastic Security remains a compelling choice for organizations seeking flexibility, transparency, and control in their cybersecurity operations.
For ongoing success, follow best practices for deployment, maintenance, and data management. Stay engaged with the Elastic community and keep abreast of new features and threat intelligence to maximize the value of your free SIEM stack.
12. Additional Resources and References
- Elastic Security Official Documentation
- CISA: SIEM Guidance
- SANS Institute: SIEM Integration Guide
- MITRE ATT&CK Framework
- Elastic Common Schema (ECS)
- FIRST: Incident Response Guide
- CrowdStrike: Network Security
- Elasticsearch Reference
- Logstash Reference
- Filebeat Reference