Overview

• In some environments and organizations, users are allowed to use browsers other than the default IE (Internet Explorer) which use settings outside of the Microsoft defaults.
  
  
• All users using browsers other than IE need to have all their traffic forwarded through GFI WebMonitor.
  
  
• This article shares the process to make sure that users cannot get around the necessary security policies by using Mozilla Firefox.
  
  
• In other words, the article shares the process for preventing users from changing GFI WebMonitor proxy settings in Firefox by using Group Policies or the GOP (Group Object Policy) editor.

Information

• Mozilla Firefox is a third-party browser with no integration with Microsoft Windows or support for remote administration by default.
  
  
• Several instruments allow users to configure Firefox like Internet Explorer remotely.
  
  
• When using Mozilla, GFI recommends that users download and use the freeware package FirefoxADM. Please note that GFI shares this information for customer convenience and does not support the FirefoxADM package.
  
  
• Download and extract the package FirefoxADM on a server with Active Directory, before proceeding with further steps mentioned in this article.

Configuring GPO to Lock Down Firefox Settings

Follow these steps to configure GPO (Group Policy Object) to run a script which will lock down the Firefox settings when the machine first starts up.

1. Open the relevant GPO for the site, domain, or organizational unit in the GPO Editor.
2. Expand the following levels within the tree: User Configuration > Windows Settings > Scripts (Logon/Logoff).
   
3. Double-click Proxy Settings in the main policy area.
4. Click the Show Files button; this displays the folder the script will be stored in.
5. Copy and paste the script file firefox_login.vbs from the FirefoxADM package into the folder.
6. Return to the Logon Properties window and click Add.
7. Browse to the location of the start scripts folder where the script was just copied.
8. Select the file and click the Open button.
9. Click OK to save the changes.

Locking down Firefox proxy settings with GPO

Follow these steps to add and configure the Administrative Templates in GPO to define the proxy settings for locking down Firefox.

1. Expand the User Configuration level in the tree.
2. Right-click Administrative Templates and select Add/Remove Templates.
3. Click the Add button and browse to the location of the startup template firefoxdefaults.adm
4. Select the file and click Open. 
5. Click Close and then expand the Administrative Templates level under Computer Configuration.
6. Select Mozilla Firefox Default Settings in the tree.
7. Double-click Proxy Settings in the main policy area.
8. Select the radio button Enabled.
   
9. Enter the proxy settings that are to be pushed to users; this information can be found in your provisioning email.
10. Once finished, click OK

This policy and any subsequent changes will only be refreshed on user login, or when a GPO update is pushed from the command prompt using the command: gpupdate /force.