Remove-BrowserHijack.ps1

#Requires -RunAsAdministrator
<#
.SYNOPSIS
Removes corporate browser hijacking (default home page, broken Restore Pages feature, etc)

.DESCRIPTION
Removes group policy registry keys that are created by IT in an attempt to waste
time by constantly directing users to a site they are not trying to visit.

.PARAMETER Install
Creates a schedueled task that will periodically remove the hijack.

.PARAMETER Uninstall
Removes the schedule task.
#>
[CmdletBinding(DefaultParameterSetName = 'Fix')]
param(
    [Parameter(ParameterSetName = 'Install')]
    [switch] $Install = $false,
    [Parameter(ParameterSetName = 'Uninstall')]
    [switch] $Uninstall = $false
)

Begin
{
    $taskName = 'Remove-BrowserHijack'

    function RegisterTask
    {
        $user = [System.Security.Principal.WindowsIdentity]::GetCurrent().Name

        $pwsh = [System.Diagnostics.Process]::GetCurrentProcess().Path
        $command = "& '${PSCommandPath}'"
        $command = [Convert]::ToBase64String([System.Text.Encoding]::Unicode.GetBytes($command))

        $action = New-ScheduledTaskAction -Execute $pwsh `
            -Argument "-NonInteractive -NoProfile -WindowStyle Hidden -ExecutionPolicy Bypass -EncodedCommand ${command}"

        $dailyTrigger = New-ScheduledTaskTrigger -Daily -At '7:00'
        $logonTrigger = New-ScheduledTaskTrigger -AtLogOn -User $user

        Register-ScheduledTask $taskName -Action $action -Trigger $dailyTrigger, $logonTrigger -User $user -RunLevel Highest
    }
	
    function UnregisterTask
    {
        Unregister-ScheduledTask $taskName
    }


    function RemoveHijack
    {
        param($0, $p)
        if (Test-Path $0)
        {
            $p | foreach { 
                if ((Get-ItemProperty $0).$_ -ne $null) {
                    Write-Host "removing $0 " -NoNewline -ForegroundColor DarkGray
                    Write-Host $_
                    Remove-ItemProperty $0 $_
                }
            }
        }    
    }

    function RemoveHijackKey
    {
        param($0)
        if (Test-Path $0) {
            Write-Host "removing $0"
            Remove-Item -Force -Recurse $0
        }
    }
}
Process
{
    if ($PSCmdlet.ParameterSetName -eq 'Install')
    {
        RegisterTask
        return
    }

    if ($PSCmdlet.ParameterSetName -eq 'Uninstall')
    {
        UnregisterTask
        return
    }

    # fix it now!

    # Chrome
    RemoveHijack 'HKCU:\SOFTWARE\Policies\Google\Chrome' @('HomePageLocation', 'RestoreOnStartup', 'ShowHomeButton')
    RemoveHijack 'HKLM:\SOFTWARE\Policies\Google\Chrome' @('HomePageLocation', 'RestoreOnStartup', 'ShowHomeButton')
    RemoveHijack 'HKCU:\SOFTWARE\Policies\Google\Chrome\Recommended' @('HomePageLocation', 'RestoreOnStartup', 'ShowHomeButton')
    RemoveHijack 'HKLM:\SOFTWARE\Policies\Google\Chrome\Recommended' @('HomePageLocation', 'RestoreOnStartup', 'ShowHomeButton')
    RemoveHijack 'HKCU:\SOFTWARE\Policies\Google\Chrome\RestoreOnStartupURLs' @('HomepageLocation')
    RemoveHijack 'HKCU:\SOFTWARE\Policies\Google\Chrome\Recommended\RestoreOnStartupURLs' @('HomepageLocation')

    RemoveHijackKey 'HKLM:\SOFTWARE\Microsoft\PolicyManager\current\device\Chrome~Policy~googlechrome~Startup'
    RemoveHijackKey 'HKLM:\SOFTWARE\Policies\Google\Chrome\RestoreOnStartupURLs'
    RemoveHijackKey 'HKLM:\SOFTWARE\WOW6432Node\Policies\Google\Chrome\RestoreOnStartupURLs'
    RemoveHijackKey 'HKLM:\SOFTWARE\WOW6432Node\Policies\Google\Chrome\Recommended\RestoreOnStartupURLs'
    RemoveHijackKey 'HKLM:\SOFTWARE\Microsoft\PolicyManager\AdmxDefault\89FA9032-04AF-4BA8-BD43-936A846F7EFE\Chrome~Policy~googlechrome_recommended~Startup_recommended'
    RemoveHijackKey 'HKLM:\SOFTWARE\Microsoft\PolicyManager\AdmxDefault\89FA9032-04AF-4BA8-BD43-936A846F7EFE\Chrome~Policy~googlechrome~Startup'
    RemoveHijackKey 'HKLM:\SOFTWARE\Microsoft\PolicyManager\Providers\89FA9032-04AF-4BA8-BD43-936A846F7EFE\default\Device\Chrome~Policy~googlechrome~Startup'

    # Edge
    RemoveHijack 'HKCU:\SOFTWARE\Policies\Microsoft\Edge\Recommended' @('HomepageLocation', 'RestoreOnStartup', 'ShowHomeButton', 'InternetExplorerIntegrationSiteList')
    RemoveHijack 'HKCU:\SOFTWARE\Policies\Microsoft\Edge\Internet Settings' @('ProvisionedHomePages')
    RemoveHijack 'HKLM:\SOFTWARE\Policies\Microsoft\Edge' @('HomepageLocation', 'RestoreOnStartup', 'ShowHomeButton', 'InternetExplorerIntegrationSiteList')

    RemoveHijackKey 'HKLM:\SOFTWARE\Microsoft\PolicyManager\current\device\microsoft_edge~Policy~microsoft_edge~Startup'
    RemoveHijackKey 'HKLM:\SOFTWARE\Policies\Microsoft\Edge\RestoreOnStartupURLs'
    RemoveHijackKey 'HKLM:\SOFTWARE\WOW6432Node\Policies\Microsoft\Policies\Microsoft\Edge\RestoreOnStartupURLs'
    RemoveHijackKey 'HKLM:\SOFTWARE\Microsoft\PolicyManager\AdmxDefault\89FA9032-04AF-4BA8-BD43-936A846F7EFE\microsoft_edge~Policy~microsoft_edge_recommended~Startup_recommended'
    RemoveHijackKey 'HKLM:\SOFTWARE\Microsoft\PolicyManager\AdmxDefault\89FA9032-04AF-4BA8-BD43-936A846F7EFE\microsoft_edge~Policy~microsoft_edge~Startup'
    RemoveHijackKey 'HKLM:\SOFTWARE\Microsoft\PolicyManager\Providers\89FA9032-04AF-4BA8-BD43-936A846F7EFE\default\Device\microsoft_edge~Policy~microsoft_edge~Startup'

    # Firefox
    RemoveHijackKey 'HKCU:\SOFTWARE\Policies\Mozilla\Firefox\Homepage'
}