SSH logging and auditing: Not as difficult as you think

Updated - 6 min read
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What is an SSH audit log or SSH audit trail?

The SSH audit log is a document or file that contains information about who accessed what and when. According to Wikipedia, an SSH audit log (also known as an SSH audit trail) is a security-relevant chronological record, set of records, and/or destination and source of records that provides documentary evidence of the sequence of activities that have affected a specific operation, procedure, event, or device at any time.

Why do you need SSH audit logging?

When a modification is made to a server, it affects the behaviour of the server. Therefore, an audit log should be kept to track the modification for future analysis and auditing purposes. To ensure security, organizations must be aware of all actions performed within their IT and network infrastructure. SSH audit logs serve as historical records and provide evidence of compliance and operational integrity. There are several reasons why SSH audit logging may be necessary:

  1. Compliance: Many regulatory bodies require organizations to maintain an audit trail of all access to sensitive data and systems, including SSH connections. Having an SSH audit log in place can help ensure compliance with these regulations.
  2. Security: SSH audit logging allows you to track any suspicious or unauthorized activity on your systems, helping you quickly identify and respond to potential security threats.
  3. Troubleshooting: SSH audit logging can be useful for troubleshooting issues that may arise on your systems. By reviewing the SSH audit log, you can see exactly what actions were taken during an SSH connection and potentially identify the cause of the problem.
  4. Auditing: SSH audit logs can be used to conduct regular audits of your systems. By reviewing the SSH audit log, you can identify any potential vulnerabilities or areas that need improvement in your security protocols.
  5. Monitoring: SSH audit logging can also be used to monitor the activity of your team members and track their productivity. This can help you identify any issues or inefficiencies that need to be addressed.
  6. Accountability: SSH audit logs can be used to hold employees accountable for their actions by providing a record of their activity on your systems.

Overall, SSH audit logging is an important tool for maintaining the security and integrity of your systems and data, and compliance with regulations.

Benefits of SSH audit logs

SSH audit logs help achieve security-related objectives, individual user accountability, reconstruction of events that occur on a system, detection of intrusions, and problem analysis.

  • Individual user accountability: SSH audit logs enable managers to monitor the actions of each team member. By utilizing restricted access controls, audit trails promote responsible user behaviour, preventing unauthorized access to or changes in data. When users are aware that their actions are being recorded in an SSH audit log, it discourages attempts to bypass security protocols. Audit logs also aid in identifying the source of errors, whether it is from the user, system, or elsewhere.
  • Intrusion detection: Intrusion detection is the process of identifying attempts to gain unauthorized access to a system. Implementing SSH audit logging on servers can aid in intrusion detection by providing real-time analysis of audit records or by reviewing them afterwards. With the help of SSH audit logs, intrusions can be detected in real time by analyzing the records as they are created or by using other types of alerts or notifications.
  • Reconstruction of events: SSH audit logs can be used to reconstruct events that have occurred on a system. By reviewing the SSH logs of system activity, it is possible to understand how, when, and why normal operations were disrupted. This information can help identify problems and prevent future incidents such as hacking, system failures, downtime, and data corruption.
  • Problem analysis: By examining the SSH audit logs, it is possible to determine the system's performance. The SSH audit logs provide crucial information, such as the user who accessed the system and when which can aid in identifying and resolving issues.

Implementing SSH audit logging using Auditd

Implementing SSH audit logging methods involves configuring your SSH server to record and log various events and activities related to SSH sessions. This can help you monitor and track user actions, detect potential security breaches, and comply with regulatory requirements. For example, here are the steps to implement SSH audit logging on a Linux Ubuntu server machine.

      # Configure SSH server to enable logging.
      $ sudo nano /etc/ssh/sshd_config
      LogLevel VERBOSE
      SyslogFacility AUTHPRIV

      # Install Auditd.
      $ sudo apt update
      $ sudo apt install auditd

      # Configure Auditd to enable logging.
      $ sudo nano /etc/audit/auditd.conf
      auditd -l -f /var/log/audit/audit.log
      max_log_file = 50

      # Add Auditd rules for SSH server.
      $ sudo nano /etc/audit/rules.d/audit.rules
      -w /var/run/sshd -p wa -k sshd
      -a exit,always -F arch=b64 -F euid=0 -S session
      -a exit,always -F arch=b64 -F euid=0 -S execve -k ssh_commands

      # Restart SSH service.
      $ sudo systemctl restart ssh.service

      # Restart Auditd service.
      $ sudo systemctl restart audit.service

Remember to regularly review and analyze the SSH audit logs to identify any suspicious activities, potential security incidents, or policy violations. Adjust the Auditd rules and log settings according to your specific requirements and security policies.

Limitations of Auditd

While Auditd is a powerful tool for audit logging, it does have some limitations that are important to consider:

  • Complexity: Configuring and managing Auditd can be complex, especially for users who are not familiar with their syntax and rules. Writing and maintaining audit rules requires understanding the specific audit rules-language, which can be challenging for beginners.
  • Performance impact: Enabling extensive auditing can have a noticeable impact on system performance. Generating and writing audit logs for every audited event can consume system resources, including CPU and disk I/O. It's important to strike a balance between the level of auditing required and the system's performance needs.
  • Disk space usage: Audit logs can accumulate rapidly, especially in environments with high levels of activity. This can result in significant disk space consumption over time. Administrators need to plan for appropriate log rotation and retention strategies to manage disk space effectively.
  • Log file readability: The audit logs generated by Auditd are typically in a binary format. Reading and interpreting the logs directly can be challenging without the use of specialized tools or utilities designed for parsing and analyzing audit logs.
  • Limited granularity: Auditd captures events at a system level, which means it may lack the granularity required for specific application-level auditing. Fine-grained auditing of application-level events may require additional configuration or the use of other specialized tools.
  • Limited coverage: Auditd focuses on system-level events and activities. It may not capture certain types of activities, such as events occurring outside the scope of the audit rules, network-based activities, or activities performed by privileged users with bypass capabilities.
  • Potential for log flooding: Misconfiguration of audit rules or an excessive number of audited events can flood the audit logs, making it difficult to find relevant information or identify important security events among the noise.

Simple solution for SSH audit logging using SloopEngine

In conclusion, using a SaaS product like SloopEngine as an alternative to Auditd can provide several advantages for audit logging and monitoring in your environment. SloopEngine offers a cloud-based solution specifically designed for audit logging, with features and benefits that address some of the limitations associated with traditional Auditd setups.

Firstly, SloopEngine simplifies the setup and configuration process. Unlike Auditd, which requires manual configuration and rule management, SloopEngine provides a user-friendly interface that allows you to easily define and customize audit policies based on your specific requirements. This eliminates the complexity associated with writing and maintaining audit rules, making it more accessible to users with varying levels of expertise.

Secondly, SloopEngine offers a scalable and efficient solution. It leverages cloud infrastructure to handle the processing and storage of audit logs, eliminating the performance impact on local systems. With SloopEngine, you don't have to worry about resource-intensive log generation or disk space limitations. The service is designed to handle large volumes of audit data effectively, ensuring optimal performance and scalability as your auditing needs grow.

SloopEngine offers a centralized dashboard that allows you to easily search, filter, and analyze audit logs in real-time. One of the standout features of SloopEngine is its ability to generate SSH logs that can be played back like a video. This unique capability allows for detailed audit analysis and facilitates the creation of comprehensive root cause analysis and post-mortem reports, which may be necessary for regulatory compliance or customer reporting requirements.

By providing SSH logs with maximum accuracy and precise time-based information, SloopEngine ensures that the audit trail is reliable, allowing organizations to effectively investigate security incidents, identify the sequence of events, and gain valuable insights for improving system security and overall operational efficiency.

Finally, SloopEngine offers the benefits of a SaaS model. It eliminates the need for infrastructure maintenance, as the service is hosted and managed by the SloopEngine team. This allows you to focus on leveraging the auditing capabilities without worrying about the underlying infrastructure, updates, or log management.

In summary, SloopEngine offers a modern and streamlined approach to audit logging, addressing many of the limitations associated with traditional tools like Auditd. Its user-friendly interface, scalability, enhanced visibility, comprehensive coverage, and SaaS convenience make it a compelling choice for organizations seeking an efficient and effective audit logging solution.

Use Case
SSH Logging & Auditing

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