Security Controls

Scripted Rules

In this section:

About Scripted Rules

VBScripts

Windows PowerShell Scripts

Sample scripts

About Scripted Rules

Scripted rules allow custom rules to be created using Windows PowerShell or VB Scripts. The success or failure of the Script determines whether the security level, Allowed Items, and Denied Items that are part of the rule apply to the user.

Scripted rules can take advantage of any interface accessible via PowerShell or VBScript, such as COM (Component Object Model).

Each script is evaluated under the following circumstances:

  • When a new configuration is deployed to the computer.

  • When a user logs on.

To create or edit scripts go to the required Scripted Rule Set in the Application Control Configuration Editor. Rule Sets > Scripted > [Rule Set name]

You can define when the script is to be run using the following Scripted Rule Options:

Run script:

Per session as user - The script runs for each user logging on. Settings are only applied for the duration of the user session.

Per session as SYSTEM - The script runs with SYSTEM account permissions once for each user logging on. Settings are only applied for the duration of the user session.

Per computer as SYSTEM - The script runs with SYSTEM account permission once at computer startup. Settings are applied to all user sessions until the computer restarts, the Application Control agent restarts or there is a configuration change.

Caution: Running scripts as the SYSTEM user can cause serious damage to your computer and should only be enabled by experienced script authors.

Wait for logon to complete - Select to prevent the script from running until user logon is complete.

VBScripts

Each script is run within a hosted script engine allowing greater control over the script execution whilst providing a high degree of input and output control.

  • No VBS file is used.
  • No separate process is spawned.

A script must be written as a function and can contain many functions, but a main start function must be specified. The start function is run by the Application Control agent and can be used to call other functions.

The AMScriptRule COM object is built into the scripting engine and provides access to the following methods:

  • strUsername = AMScriptRule.UserName

  • strUserdomain = AMScriptRule.UserDomain

  • strSessionid = AMScriptRule.SessionID

  • strStationname = AMScriptRule.WinStation

    The Microsoft standard in this instance means that WinStation returns the value of the name of the Terminal Services Session, which is determined by the type of session with typical values being ’Console’ or ’RDP-Tcp#34’, instead of the Window Station name which is typically WinSta0.

The AMScriptRule COM object also includes the following methods:

  • strLog = AMScriptRule.Log "My Log Statement"

    Allows you to output logging strings to the agent log file for use with debugging scripted rules.

  • strEnvironmentvar = AMScriptRule.ExpandEnvironment ("%MyEnvironmentVariables%")

    Expands environment variables of the user running the script.

Using WScript. shell to expand environment variables only returns SYSTEM variables.

Windows PowerShell Scripts

If the script returns (exits) with a value of 0, the script will pass and the rules are applied. If any non-zero value is returned, the script will fail and the rules will not apply.

Each PowerShell script is executed in an instance of PowerShell.exe and as such Application Control neither enforces nor adds any specific syntax – all correctly formed PowerShell will work.

PowerShell must be installed on any endpoints that will be using the script.

Sample scripts

Related Topics

Rule Sets

Rule Collections


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