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Audit logs, otherwise referred to as audit trails, are detailed records that document activities or a sequence of activities or events. Typically, they deal with the usage of systems, applications, and/or networks. They are crucial in ensuring security, compliance, and operational oversight and enable users to keep track of the history of all actions executed and who has done what and when.
Monitoring audit logs is critical to both security and compliance, as well as the operational integrity of an enterprise's information technology infrastructure. Audit logging creates an extended on-the-record view of the activities of a system and those performed by users that can be critical in detecting and responding to security incidents. This monitors the logs for an organization to identify unauthorized access attempts or any other suspicious behavior indicative of a potential breach, enabling them to intervene on time and reduce the risk.
Having highlighted the importance of audit logging, it’s clear why numerous organizations utilize the practices to enhance their security and compliance operations. However, not all of these organizations know how to conduct audit logging efficiently. So to assist with this process, in this article we will outline the audit logging best practices, to support your organization in gaining the most from the practice.
Contents
What is Audit Logging?
Audit logging involves the creation and maintenance of a chronological record of activities, events, and transactions occurring on a system or across a network. It captures information of importance regarding actions executed by users, applications, or systems, and creates a record of what happened, when it happened, and who was involved. Audit logging is also one of the core integral parts of system management and security, providing insights into the functioning and usage of IT resources.
What Activities Can Audit Logs Track?
- User Access and Authentication: Records details of user logins, logouts, and failed login attempts with timestamps, IPs, and user IDs. In doing so, it builds up trends of access that identify unauthorized access.
- Data Access and Modifications: It keeps track of all activities on data retrieval, creation, modification, and deletion. This ensures that access to sensitive data is monitored and unauthorized changes can be detected.
- System and Application Changes: The audit trail keeps changes to the system configurations, application settings, and software installations or updates. This helps maintain an administrative record of actions and configuration changes.
- Network Activity: Monitors network connections and communications, including the source and destination IP addresses, ports, and protocols used, aiding in the detection of suspicious network behavior and potential security breaches.
- Error and Failure Events: Captures system errors, application crashes, and hardware failures, giving insights into operational issues and helping with troubleshooting and problem resolution.
- File and Resource Access: Maintains a log of every access to files, directories, and other resources; it captures who performed this action, what exactly was done, and when. In doing so, this provides for proper monitoring and control over critical resources.
Audit Logging Best Practices
Effective and Extensive Logging Strategy
A robust audit logging strategy needs to log events across all critical systems and applications. These would include servers, databases, network devices, and endpoint devices. The logs allow for a complete record of each important activity, thereby giving a snapshot of the organizational IT environment. It's important to determine what events are to be logged, considering their importance and potential security and operational impact. Typical logged events would be user access, state changes to data, system configuration changes, and security-related events.
Consistent and Accurate Timestamping
Timestamps are a crucial aspect of an audit log as they allow for a pristine chronology of events. Log entries from independent systems can also be correlated if all systems are synchronized with a reliable time source, such as an NTP server. This is particularly useful in forensic investigations, where it allows an analyst to reconstruct a timeline of events leading up to an incident.
Secure Log Storage
The integrity and confidentiality of audit logs have to be protected, therefore, they should be maintained in a secure and centralized repository with limited access for modification and deletion. Log data should be encrypted both in transit and at rest. Strict access controls need to be in place, ensuring that only certain people within the organization have the authority to view or handle logs and, in turn, maintain their integrity and confidentiality.
Regular Log Review and Analysis
All organizations should regularly review and analyze audit logs for anomaly detection, which may signal the occurrence of a possible security incident. Automated log analysis tools, such as Security Information and Event Management (SIEM) systems, provide real-time event correlation and alerting to specified activities. They assist with active monitoring, allowing the organization to quickly respond to potential threats. Complementing automated analyses through periodic manual review of the logs ensures more in-depth insight and context, potentially too subtle for automated systems to pick up.
Retention Policies and Compliance
Audit logs should be stored for a suitable period, which is rightly governed by the regulatory requirements and organizational policies. There needs to be a fine line drawn between retention policies against historical data with respect to limitations on storage and performance considerations. Logs must be kept in place for specified periods, and there must be a process to securely dispose of logs when not required anymore.
Regular Testing and Auditing
Continuous testing and auditing of the audit logging system itself are important in proving its effectiveness. Checks should be made to see that all critical events are logged with appropriate information, the logs themselves are suitably protected against tampering, and that the alerting mechanisms are working properly. Periodic audits identify gaps or weaknesses in the logging process and open avenues for continuous improvement and adapting to evolving threats.
Documentation and Training
Thorough documentation on the audit logging strategy, policies, and procedures is necessary for consistency and clarity. All this documentation has to be available to relevant personnel, and reviewed continuously to ensure updating in view of changes to the IT environment or regulatory requirements. Equally important in the effective utilization of its logging capabilities by an organization is the training of staff in the importance of audit logging, how to interpret the logs, and how to react to alerts.
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