How can you audit and monitor IIS logs for security?

1 Enable and configure IIS logging

The first step to audit and monitor IIS logs for security is to enable and configure IIS logging on your web server. IIS logging is not enabled by default, so you need to turn it on and choose the log format, location, and fields that you want to record. You can do this from the IIS Manager console, or by editing the web.config file of your website or web application. You can also use PowerShell commands to automate the process. You should choose a log format that is compatible with your log analysis tool, such as W3C, NCSA, or IIS. You should also select a log location that is secure and has enough disk space. Finally, you should choose the log fields that are relevant for your security analysis, such as date, time, IP address, user name, method, URL, status code, bytes sent and received, and user agent.

2 Analyze and filter IIS logs

The next step to audit and monitor IIS logs for security is to analyze and filter IIS logs using a log analysis tool. A log analysis tool can help you parse, visualize, and query your IIS logs, and detect any anomalies, errors, or suspicious activities. Some examples of log analysis tools are Log Parser Studio, Log Analyzer, and Loggly. You can use these tools to filter your IIS logs by criteria such as date range, IP address, user name, status code, method, URL, or user agent. You can also use these tools to create reports and dashboards that show the trends, patterns, and statistics of your web traffic and security events.

3 Monitor and alert on IIS logs

The third step to audit and monitor IIS logs for security is to monitor and alert on IIS logs using a log monitoring tool. A log monitoring tool can help you collect, aggregate, and stream your IIS logs in real time, and alert you when something goes wrong or needs your attention. Some examples of log monitoring tools are Splunk, Datadog, and SolarWinds. You can use these tools to set up thresholds, rules, and triggers for your IIS logs, and receive notifications via email, SMS, or other channels. You can also use these tools to integrate your IIS logs with other data sources, such as performance metrics, network traffic, or security events.

4 Review and archive IIS logs

The fourth step to audit and monitor IIS logs for security is to review and archive IIS logs on a regular basis. You should review your IIS logs periodically to check for any issues, errors, or incidents that may have occurred, and take appropriate actions to resolve them. You should also archive your IIS logs to a secure and reliable storage location, such as a cloud service, a backup server, or a tape drive. You should keep your IIS logs for as long as you need them for compliance, audit, or forensic purposes, and delete them when they are no longer needed.

5 Secure and protect IIS logs

The fifth step to audit and monitor IIS logs for security is to secure and protect IIS logs from unauthorized access, modification, or deletion. You should apply the principle of least privilege to your IIS logs, and grant access only to those who need it. You should also encrypt your IIS logs, both in transit and at rest, to prevent data breaches or tampering. You should also use a log integrity tool, such as Tripwire, to verify the authenticity and integrity of your IIS logs, and detect any changes or corruption.

6 Update and patch IIS

The sixth and final step to audit and monitor IIS logs for security is to update and patch IIS regularly. You should keep your IIS up to date with the latest security updates, patches, and hotfixes, to prevent vulnerabilities and exploits. You should also follow the best practices for IIS security and hardening, such as disabling unnecessary features, services, and protocols, enabling HTTPS and SSL, enforcing strong authentication and authorization, and applying firewall rules and security policies.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?