18.9.100.1 Ensure 'Turn on PowerShell Script Block Logging' is set to 'Enabled'

Information

This policy setting enables logging of all PowerShell script input to the Applications and Services Logs\Microsoft\Windows\PowerShell\Operational Event Log channel.

The recommended state for this setting is: Enabled.

Note: If logging of Script Block Invocation Start/Stop Events is enabled (option box checked), PowerShell will log additional events when invocation of a command, script block, function, or script starts or stops. Enabling this option generates a high volume of event logs. CIS has intentionally chosen not to make a recommendation for this option, since it generates a large volume of events. If an organization chooses to enable the optional setting (checked), this also conforms to the benchmark.

Rationale:

Logs of PowerShell script input can be very valuable when performing forensic investigations of PowerShell attack incidents to determine what occurred.

Impact:

PowerShell script input will be logged to the Applications and Services Logs\Microsoft\Windows\PowerShell\Operational Event Log channel, which can contain credentials and sensitive information.

Warning: There are potential risks of capturing credentials and sensitive information in the PowerShell logs, which could be exposed to users who have read-access to those logs. Microsoft provides a feature called 'Protected Event Logging' to better secure event log data. For assistance with protecting event logging, visit: About Logging Windows - PowerShell | Microsoft Docs.

Solution

To establish the recommended configuration via GP, set the following UI path to Enabled:

Computer Configuration\Policies\Administrative Templates\Windows Components\Windows PowerShell\Turn on PowerShell Script Block Logging

Note: This Group Policy path may not exist by default. It is provided by the Group Policy template PowerShellExecutionPolicy.admx/adml that is included with the Microsoft Windows 10 RTM (Release 1507) Administrative Templates (or newer).

Default Value:

Enabled. (PowerShell will log script blocks the first time they are used.)

See Also

https://workbench.cisecurity.org/files/4022

Item Details

Category: AUDIT AND ACCOUNTABILITY

References: 800-53|AU-2, CSCv7|8.8

Plugin: Windows

Control ID: 8751eb3957e211e2a5b176ec1a3134013ece0d7adb7d8c2b0c19f3415ffcd7c8