Security logging is a critical part of modern cybersecurity, providing the foundation for detecting, analyzing, and responding to potential threats. As highlighted by OWASP, security logging and monitoring failures can lead to undetected security breaches. With the average cost of a data breach adding up to $4.45 million, most organizations can’t afford to miss a security incident.
For today’s Security Operations Center (SOC), effective security event logging is essential to maintain the integrity and security of an organization’s systems and applications. Doing so provides comprehensive visibility into all activities across the IT environment. This visibility is crucial for detecting and responding to security incidents in real-time, identifying potential vulnerabilities, and ensuring compliance with regulatory requirements. In addition, thorough logging supports forensic investigations and threat hunting by creating an audit trail of all security events, which helps trace the origins of any suspicious or unauthorized actions.
Want to master security logging? Let’s explore the top five best practices to help you handle potential threats as they emerge.
1. Ensure Comprehensive Log Collection
Comprehensive log collection is the first step in building a robust security logging strategy. By logging all critical systems and applications, you can capture a complete picture of your IT environment, making it easier to detect and respond to security incidents. The good news is that many of the log data types typically used in log management for DevOps can be applied to a security use case, as well. Looking at log data is especially important, as sophisticated attackers often use legitimate IT tools to hide in plain sight.
Examples of Critical Log Data to Evaluate
Below are log data types security operations teams can review regularly.
- System Logs: System logs track system-level events such as user logins, system errors, and configuration changes. These logs are vital for identifying unauthorized access or system vulnerabilities. Monitoring system logs helps in maintaining the overall health and security of your IT infrastructure.
- Application Logs: Application logs record application-specific events like user interactions, errors, and performance metrics. These logs are crucial for detecting application-layer attacks or abnormal behavior that could indicate a security breach or performance issue.
- Network Logs: Network logs capture network traffic data, including source and destination IP addresses and protocols used. These logs are essential for identifying suspicious network activities such as unauthorized access or data exfiltration attempts.
- Security Logs: Security logs document security-related events like firewall blocks, antivirus activity, and intrusion detection alerts. These logs are crucial for spotting and responding to potential security breaches, helping to safeguard your organization’s assets.
- Audit Logs: Audit logs provide a detailed trail of user activities and system changes. These logs help ensure accountability and trace the origins of suspicious or unauthorized actions, making them invaluable for compliance and forensic investigations.
2. Maintain Log Integrity and Security
Log integrity refers to the accuracy and trustworthiness of log data. Maintaining log integrity ensures that the data has not been tampered with and is reliable for security analysis and compliance purposes. Many attackers will attempt to modify log data to hide their trails, through techniques like log injection, deletion, or alteration.
How to Ensure Logs Aren’t Tampered With
- Hashing: Applying cryptographic hash functions to log entries creates a unique hash value for each entry. By comparing these hash values over time, you can detect any alterations, ensuring data integrity.
- Encryption: Encrypting log data both at rest and in transit using strong encryption algorithms protects sensitive information from unauthorized access and tampering. This method secures log data against potential breaches.
- Access Controls: Implementing strict access controls and role-based permissions limits who can view, modify, or delete log data. Coupled with audit trails to monitor and log access attempts, this practice enhances the security of your logs.
3. Analyze Long-term Logs for Threat Hunting
Regular log analysis and review is a critical part of establishing and maintaining a proactive security posture. Routine reviews help in identifying anomalies, detecting potential threats, and ensuring compliance with security policies. Using threat hunting, teams can use established methodologies like the MITRE ATT&CK Framework to search for threats that may be lingering undetected in your systems.
Retaining logs for an extended period is essential for identifying long-term trends and improving the understanding of system behavior. Long-term data retention aids in historical analysis, compliance, and forensic investigations.
Techniques for Effective Log Analysis and Threat Hunting
- Anomaly Detection: Identifying deviations from normal behavior patterns in log data (such as the data stored in a security data lake) can uncover unusual or suspicious activities that may indicate security threats. This proactive approach helps in early threat detection.
- Correlation Analysis: Cross-referencing and correlating log entries from multiple sources, such as system logs, network logs, and application logs, can help detect complex attack patterns and provide a comprehensive view of potential security incidents.
- Threat Intelligence Integration: Incorporating threat intelligence feeds and databases into log analysis processes enables matching log data against known indicators of compromise (IOCs) and signatures of emerging threats. This integration facilitates proactive identification and response to potential security issues.
4. Implement Real-Time Log Monitoring and Alerts
Real-time monitoring is crucial for the immediate detection of security incidents. It complements long-term log analysis and threat hunting by providing instant alerts to emerging security incidents, allowing for faster incident response times.
Automated alerts for suspicious activity ensure timely responses to potential threats. Setting up these alerts involves configuring thresholds and conditions based on your security policies and risk tolerance, with the goal of reducing false positives.
Implementing Security Information and Event Management (SIEM) or Security Orchestration, Automation, and Response (SOAR) tools can enhance real-time log analysis. These tools provide robust monitoring and alerting capabilities, yet may be cost-prohibitive for many companies for long-term log analysis (we’ll address this next).
5. Utilize Centralized Log Management on a Data Lake
A centralized log management system offers a number of benefits, including reduced costs, enhanced visibility, and improved accuracy in threat investigation. By unifying data from different security tools, a centralized platform provides a single source of truth for your security operations.
For example, a platform like ChaosSearch leverages existing cloud object storage (e.g. Amazon S3) to reduce costs and enable the analysis of higher volumes of log data for longer periods of time. This strategy can complement the real-time capabilities of a SIEM or SOAR, where long-term log ingestion and retention costs often become untenable.
ChaosSearch can also be used with a security data lake to enhance the detection of long-term trends. It allows you to analyze data in different formats without data movement, streamlining threat investigation and improving accuracy.
The Importance of Effective Security Logging
Effective security logging is essential for maintaining the integrity and security of an organization’s data, systems, and applications. By following the best practices outlined above, you can enhance your security logging strategy. As a result, you can significantly improve your organization's ability to detect, analyze, and respond to security threats, enhancing your overall cybersecurity posture.
