Security Information and Event Management (SIEM) is a comprehensive approach to security management, combining security information management (SIM) and security event management (SEM) functionalities. It’s a system that aggregates event, threat, and risk data into a centralized platform. The primary goal of a SIEM is to enhance the detection, analysis, and response to security incidents, providing a robust, layered defense strategy. While a SIEM can significantly improve security posture, effective implementation requires careful consideration of security business processes and data integration to maximize its potential.
Understanding the Power of Audit Data
Audit logging and meticulous review are fundamental components of any robust strategy aimed at securing vital IT assets and sensitive data. Many organizations collect substantial audit log data, yet they often struggle to extract actionable insights due to its sheer volume and inherent complexity.
Properly leveraging log data provides support to several crucial security objectives:
- Threat Detection: Identifying both known and emerging threats in real-time.
- Vulnerability Assessment: Pinpointing weaknesses in systems and applications.
- Accelerated Incident Response: Streamlining the response to security incidents.
- Policy Violation Identification: Detecting deviations from established security policies.
- Forensic Evidence: Providing crucial data for investigations following a security breach.
Furthermore, compliance standards, such as Publication 1075, “Tax Information Security Guidelines for Federal, State, and Local Agencies,” mandate the detection of unauthorized access to Federal Tax Information (FTI) data through security-relevant event auditing. Auditing capabilities must be maximized to capture all access, modification, deletion, and movement of FTI by each unique user.
Evaluating and Understanding SIEM Systems
A SIEM system is architected to streamline data collection, analysis, and incident response workflows. Modern SIEMs are capable of ingesting and processing a wide variety of event types and configuration data, leading to potentially massive data volumes. Unstructured data collection and compilation can severely hinder effective data evaluation, preventing the delivery of actionable intelligence needed to strengthen an organization’s security profile.
SIEM systems have become central to security programs, providing valuable insights to operations, compliance, and security and risk teams, helping them to support key business and security functions. These tools can supply a comprehensive view of activities across an organization’s network.
Key capabilities of a SIEM system include:
Scalability: The volume of security events is constantly increasing, along with the number of applications, users, and devices that generate logs. Stakeholders require the capture of additional event types to aid in reporting and analysis. Successfully managing the explosion of event data requires thoughtful planning, implementation, and ongoing management.
Forensics: A SIEM platform should offer automated data analysis, enhanced notifications, and data enrichment. These features provide operations staff with crucial contextual data, reducing their workload and improving the speed and accuracy of incident investigation. Advanced platforms offer pre-built analysis policies and seamless event correlation, enhancing drill-down capabilities.
Speed: Modern SIEM systems must deliver near real-time results. They are no longer just repositories of historical data. Instead, they function as frontline security tools for continuous monitoring and detecting misuse and attacks against critical IT assets. Actionable alerts and insights should be available as close to real-time as possible.
Ease of Use: Intuitive interfaces, quick setup, streamlined training, and automated tasks are crucial elements of a modern SIEM platform. However, maintaining a SIEM system requires ongoing investment in resources, including budget and skilled personnel. SIEM vendors have continually enhanced their platforms with automated rules, improved user interfaces (UI), and threat and policy management dashboards to simplify day-to-day use and reduce administrative overhead.
Utilizing SIEM for Compliance with Publication 1075 Controls
A well-implemented SIEM solution can facilitate an agency’s compliance with the Audit and Accountability controls outlined in Pub. 1075, Section 4.3. When deploying a SIEM tool to support audit log data review, agencies should refer to the following guidelines:
Audit and Accountability Policy and Procedures (AU-1): Deploying a SIEM may necessitate updates to existing policies and procedures related to auditing. Well-defined policies and procedures are crucial for the successful collection, correlation, and reporting of audit log data. These should clearly outline requirements, roles, responsibilities, and standards. Regular review ensures ongoing relevance. Policies should be reviewed at least every three years, while procedures should be reviewed annually.
Audit Events (AU-2): Auditing should be maximized to capture every instance of access, modification, deletion, and movement of FTI by individual users. Agencies need to capture all security and administrative actions, in addition to user activity involving FTI. This encompasses activities such as system logons/logoffs, use of administrative commands, permission changes, and any interaction with FTI. Agencies should also consult platform-specific auditing requirements detailed in the Safeguards Computer Security Evaluation Matrices (SCSEMs).
Furthermore, agencies must collaborate with other internal entities that require audit-related information to define appropriate auditable events aligned with their needs.
Once established and configured in the SIEM environment, these events should be reviewed at least annually to ensure their capture is effectively supporting the agency’s information security requirements.
Content of Audit Records (AU-3): Every system sending log data to the SIEM must provide sufficient information to define the type of event that occurred, the time of the event, the location of the event, the source of the event, the outcome of the event, and the identity of any individuals or subjects involved.
The SIEM solution can standardize the content and format of log data to facilitate review and correlation. However, administrators must guarantee that all relevant log data elements are captured.
Audit Storage Capacity (AU-4): Centralized capture and storage of audit log data from a large number of systems across the organization requires sufficient storage capacity. Pub. 1075 mandates that seven years of data be retained for all systems that store, transmit, process, and/or receive FTI.
Response to Audit Processing Failures (AU-5): The SIEM solution must be configured to generate real-time alerts when audit processing fails on a connected system. Additionally, storage capacity should be closely monitored to prevent data loss and to ensure sufficient space for current logs.
Audit Review, Analysis, and Reporting (AU-6): Even with a SIEM solution providing correlation and automated alerts, weekly manual review by administrators, security teams, and business managers remains necessary. For example, manually verifying the appropriateness of employee access to FTI cannot be completely automated. However, the SIEM solution can be customized to generate reports of this data and manage its review process. Reports can be tailored to various organizational needs, distributed automatically, and their review process logged.
Staff must receive training on how to interpret alerts and effectively use standardized and ad hoc reports for both security and access-related events.
Audit Reduction and Report Generation (AU-7): A key characteristic of a SIEM solution is its capacity to correlate logs across multiple systems and analyze data for anomalies and potential threats. Agencies must define alert thresholds for administrators and/or security staff. Fine-tuning may be necessary as the SIEM solution evolves, with consideration given to the resources available to review and resolve alerts. All generated alerts must be logged, acknowledged by an administrator, and the disposition of the alert must be recorded.
Furthermore, the log data should be accessible to authorized personnel for on-demand review and to support post-incident investigations.
Time Stamps (AU-8): To correlate log data accurately, all systems must synchronize with a standard, authoritative time server (e.g., NIST, Naval Observatory).
Protection of Audit (AU-9): Audit log data is highly sensitive, especially if it includes FTI. Access to this data should be restricted to authorized personnel only, and any modifications or deletions of the data must be logged.
Cross-Organizational Auditing Logging (AU-16): Agencies must maintain awareness of all systems that store, transmit, process, and/or receive FTI, even if those systems are operated by a third party. External data from outsourced data centers or cloud providers can be integrated into the SIEM solution to provide additional analysis capabilities.
Conclusion
Implementing and effectively managing a SIEM solution is a critical component of modern cybersecurity. By centralizing log data, automating analysis, and providing real-time alerts, SIEM systems empower organizations to proactively detect, respond to, and mitigate security threats. When properly configured and integrated with security policies and compliance requirements, a SIEM can be a powerful tool for protecting sensitive data and ensuring a strong security posture. Take the first step today to strengthen your organization’s security – explore the possibilities a SIEM solution can bring.
