Sysmon

Overview

Sysmon (System Monitor) is a Windows system service and driver from Microsoft’s Sysinternals suite. It provides detailed logging of system activity, which goes beyond native Windows auditing capabilities. Sysmon helps in tracking process creation, network connections, and other system-level activities for forensic investigations, threat hunting, and incident response.

Key Features of Sysmon:

  1. Process Monitoring:

    • Logs process creation, including process ID, command line, and hashes.

    • Captures process termination events.

  2. Network Monitoring:

    • Tracks network connections, including IP addresses, ports, and protocols.

    • Monitors DNS query events for domain lookups.

  3. File and Registry Monitoring:

    • Detects changes to file creation time (even if altered retroactively).

    • Monitors registry modifications and event access attempts.

  4. Driver and DLL Loading:

    • Captures details of drivers and DLLs loaded into processes.

  5. Event Forwarding:

    • Logs are integrated with Windows Event Log, making them accessible via tools like Event Viewer or SIEM solutions.

  6. Hashing and Data Integrity:

    • Hashes of processes (MD5, SHA-1, SHA-256) are captured to detect tampered or malicious files.

Why Sysmon is Important:

  • Granular Monitoring: Sysmon complements basic and advanced auditing by offering more detailed telemetry.

  • Threat Detection and Forensics: It enables early detection of suspicious activities, like unusual process launches or unauthorized network connections.

  • Customization with Configuration Files: Administrators can tune Sysmon’s behavior via XML configuration files to reduce noise and focus on critical events.

Deployment and Usage:

  • Installation: Download and install Sysmon from the Sysinternals site. The service runs persistently in the background.

  • Configuration: Use XML configuration files to define which activities are logged. Example commands:

    sysmon.exe -accepteula -i config.xml

    This installs Sysmon with your custom rules.

  • Event Analysis: Sysmon events appear under "Microsoft-Windows-Sysmon/Operational" in Event Viewer, making them easy to collect and analyze.

Comparison to Windows Auditing:

  • Sysmon offers more detailed event logging than native Windows security auditing.

  • It captures more context-rich data, such as process command-line arguments and DNS queries, which are either unavailable or harder to configure in Advanced Security Auditing.

Documentation

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