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What Is Audit Logging? How It Works & Why You Need It

by Chris Brook on Monday April 22, 2024

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An audit log is a document that records the activities within an application, system, or network. Learn more about audit logging in today's blog.

Crime novels’ investigative plots rely on protagonists tracking evidentiary data to expose the perpetrators responsible for their marquee crimes. But you don’t have to be Sherlock Holmes to grasp the importance of audit trails and logs for effective data protection in cybersecurity. 

What Is An Audit Log?

An audit log is a document that records the activities within an application, system, or network. It provides an orderly, time-stamped record of individual events, the associated user, and the nature of the action.


Audit logs track user activity, assist in troubleshooting, verify system security, and ensure compliance with regulatory requirements. They are essentially a form of evidence providing details about when, where, and by whom a specific action was carried out inside a system.

What Are Audit Log Use Cases?

  • Regulatory Compliance: Various industry regulations require companies to keep a record of their system and user activities. For example, audit logs are necessary for HIPAA, SOX, PCI DSS, and GDPR compliance. They can help reveal non-compliance and prevent potential penalties.
  • Security Monitoring: Audit logs can help detect suspicious user behavior or system anomalies and identify potential security threats or breaches. This can help detect and prevent the theft of intellectual property. By recording all user activities, audit logs provide a detailed view of who did what and when. 
  • IT Forensics: Audit logs act as a source of forensic evidence in a security incident. They allow analysts to reconstruct events, understand how an incident happened, and take preventative measures for the future.
  • System Troubleshooting: Audit logs record all system events, including errors. This makes them vital for system troubleshooting to diagnose and fix operational problems.
  • Accountability: Audit logs can prove or disprove responsibility for actions, particularly those leading to negative outcomes. For example, they can help identify who made a mistake or violated company policy. It also allows organizations to pinpoint the root of data compromises.
  • Operational Analysis: By providing a record of all operations, audit logs are a rich operational data source. They can be used for performance monitoring, capacity planning, and identifying areas for system improvement.
  • Legal Evidence: In the event of a legal dispute, audit logs can serve as legal evidence due to their accurate record of user actions and system responses.
  • Change Management: Audit logs are critical in accurately tracking system, application, or database changes. They can aid in the rollback of changes and help identify unauthorized modifications.

What Do Audit Logs and Audit Trails Document?

Audit logs and audit trails document a complete historical record of system actions and activities. They serve as a security measure to monitor and verify system activities, ensure compliance, and aid in troubleshooting and forensic investigations. 


Here are some key types of information documented in audit logs and trails:

  • User Activity: The actions of individual users, such as the time they logged in or out, the resources they accessed, and the changes they made to data or system settings. 
  • System Events: Important system-related activities, such as system start-ups or shutdowns, system errors or failures, and security-related events.
  • Data Access and Modifications: Any actions related to accessing, creating, viewing, modifying, or deleting data. This helps track how data is being used and by whom.
  • Transaction History: Detailed records of all transactions processed by the system, such as financial transactions in a banking system or order placements in an e-commerce platform.
  • Security Incidents: Any potential or actual security breaches, failed login attempts, changes to access rights, and activations of virus-detection software.
  • Configuration Changes: Any changes made to the system's configuration settings, including software installations, updates, or modifications to network settings.
  • Administrative Actions: Actions performed by system administrators, such as user account creation, privilege assignments, system backups, or system restore operations.

What Types of Activity Do Audit Logs Track?

Audit logs can track a variety of system activities. This includes but is not limited to:

  • Login and Logout: This includes successful and unsuccessful attempts. 
  • Access to Sensitive Data: Any attempts to read, modify, copy, or delete sensitive data are tracked.
  • Changes in User Permissions: Any changes to system or data access permissions or roles. 
  • System and Configuration Changes: Any system configurations or settings modifications.
  • Network Activities: Information about requests for accessing network resources or alterations in network configuration.
  • User Actions: Activities performed by a user in a system such as file editing, system command execution, and data creation.
  • Application Activities: Any interactions with software applications like updates/installations, starting/stopping applications, and any modifications made within the application.
  • Security Events include any alterations to security policies or control systems, detection of viruses or malware, and firewall function. 
  • Errors or System Failures: Any application or system errors, crashes, or performance issues.
  • Transaction Histories: In systems handling transactions, such as payment gateways or databases, logs of all transactions are maintained. 

What to Look For in An Audit Logging Tool

There are several key features and capabilities to look for when choosing an audit logging tool:

  • Real-Time Monitoring: A good logging tool should allow for real-time monitoring and the ability to send real-time alerts when certain events of interest occur.
  • Easy to Read and Understand: Logs should be easy to read and understand. The tool should organize and present log data in a clear way, perhaps with graphs or charts for easier comprehension.
  • Compatibility: The logging tool should be compatible with your current systems. If you use multiple systems, it is important that the tool is able to integrate with all of them.
  • Scalability: The tool should be able to handle large volumes of log data and scale accordingly as your business grows.
  • Log Management: Log management capabilities, including collecting, storing, and analyzing logs, are important. A suitable tool would retain logs for an appropriate amount of time per an organization's regulation requirement.
  • Security Features: Look for tools that provide encryption and secure log access. The tool itself should also be protected from vulnerabilities.
  • Compliance: Consider whether the tool helps you comply with relevant industry standards or regulations (e.g., GDPR, HIPAA, PCI DSS).
  • Automated Analysis: A good logging tool can automatically analyze log data and generate reports based on the analysis.
  • Easy to Use: The logging tool should be easy to use, with a user-friendly interface and straightforward set-up process.
  • Customizability: The ability to customize the tool to your specific needs is beneficial. This can include creating custom alerts or reports.
  • Cost: Evaluate the pricing structure of the tool, considering your budget and the return on investment it offers.
  • Support: Check if the software vendor provides reliable support if you need help with setup, troubleshooting, or queries.

The Benefits of Keeping An Audit Log

Audit logs are critical for various reasons and offer several benefits:

  • Accountability: Audit logs provide a record of who did what and when. This creates an environment of accountability, as all actions can be traced back to individual users.
  • Security: Audit logs can help identify potential security breaches or fraudulent activities by tracking all system activity. They allow system administrators to spot unusual patterns or behaviors that may signify a cyber attack or misuse.
  • Compliance: For many industries, maintaining detailed audit logs is not just good practice but a legal requirement. This is particularly true in industries that handle sensitive data, such as healthcare or finance, where regulations like HIPAA or PCI DSS require certain logging levels.
  • Troubleshooting: Audit logs can provide crucial insights when diagnosing and resolving technical issues. They offer a record of system events leading up to an error, making it easier to identify the problem and implement a solution.
  • Forensics: Audit logs are often used for forensic investigation in case of a security incident. The detailed records can help determine how a breach occurred and what data was affected, helping to prevent future incidents.
  • Operational Efficiency: Audit logs can provide valuable insights into system usage and user behavior, which can be used to improve processes and enhance operational efficiency.
  • Legal Protection: Detailed audit logs can also provide critical evidence in legal disputes, demonstrating due diligence and protecting the organization against potential lawsuits.

Learn How Digital Guardian Can Help with Your Audit Logging Needs

Digital Guardian understands how the benefits of audit logs extend to improved security systems that track user behavior and data, whether at rest or in transit. 


To identify potential security threats with audit logging, schedule a demo with us to learn more.


Tags:  Data Protection Data Security

Chris Brook

Chris Brook

Chris Brook is the editor of Digital Guardian’s Data Insider blog. He is a cybersecurity writer with nearly 15 years of experience reporting and writing about information security, attending infosec conferences like Black Hat and RSA, and interviewing hackers and security researchers. Prior to joining Digital Guardian–acquired by Fortra in 2021–he helped launch Threatpost, an independent news site that was a leading source of information about IT and business security for hundreds of thousands of professionals worldwide.

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