三好学生 · 2015/09/07 10:20

0x00 前言

前两篇分别介绍了WMI Attacks & WMI Backdoor，侧重于攻击，所以这篇介绍一下WMI Defense，攻防结合，便于大家更清楚认识WMI.

0x01 简介

本篇侧重于介绍如何通过Powershell调用WMI监视自身系统、记录入侵行为，并对WMI的检测工具做具体测试。

0x02 测试环境

Win8 x86 powershell v3（win8默认安装） 开启Winmgmt服务，支持WMI

0x03 监视系统

*注： 以下均为Powershell代码

1、监视进程创建

 $filterName = 'BotFilter48'$consumerName = 'BotConsumer48'#查询进程创建事件$Query = "SELECT * FROM __InstanceCreationEvent WITHIN 5 WHERE TargetInstance ISA 'Win32_Process'"$WMIEventFilter = Set-WmiInstance -Class __EventFilter -NameSpace "root\subscription" -Arguments @{Name=$filterName;EventNameSpace="root\cimv2";QueryLanguage="WQL";Query=$Query} -ErrorAction Stop#写入日志文件$Arg =@{Name=$consumerNameFilename = 'C:\test\log.log'Text = 'New Process Created with name %TargetInstance.Name%'}$WMIEventConsumer = Set-WmiInstance -Class LogFileEventConsumer -Namespace "root\subscription" -Arguments $ArgSet-WmiInstance -Class __FilterToConsumerBinding -Namespace "root\subscription" -Arguments @{Filter=$WMIEventFilter;Consumer=$WMIEventConsumer}
复制代码

如图

2、监视进程结束

$filterName = 'BotFilter49'
$consumerName = 'BotConsumer49'# 查询进程结束事件$Query = "SELECT * FROM __InstanceDeletionEvent WITHIN 5 WHERE TargetInstance ISA 'Win32_Process'"
$WMIEventFilter = Set-WmiInstance -Class __EventFilter -NameSpace "root\subscription" -Arguments @{Name=$filterName;EventNameSpace="root\cimv2";QueryLanguage="WQL";Query=$Query} -ErrorAction Stop$Arg =@{Name=$consumerNameFilename = 'C:\test\log.log'Text = 'Task kill with name %TargetInstance.Name%'}
$WMIEventConsumer = Set-WmiInstance -Class LogFileEventConsumer -Namespace "root\subscription" -Arguments $ArgSet-WmiInstance -Class __FilterToConsumerBinding -Namespace "root\subscription" -Arguments @{Filter=$WMIEventFilter;Consumer=$WMIEventConsumer}
复制代码

如图

3、监视注册表

（1）监视单一键值

$filterName = 'BotFilter51'
$consumerName = 'BotConsumer51'$Query ="SELECT * FROM RegistryKeyChangeEvent WHERE Hive='HKEY_LOCAL_MACHINE' AND KeyPath='SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run'" $WMIEventFilter = Set-WmiInstance -Class __EventFilter -NameSpace "root\subscription" -Arguments @{Name=$filterName;EventNameSpace="root\default";QueryLanguage="WQL";Query=$Query} -ErrorAction Stop$Arg =@{Name=$consumerNameFilename = 'C:\test\log.log'Text ='The change is HKEY_LOCAL_MACHINE\\%KeyPath%'}$WMIEventConsumer = Set-WmiInstance -Class LogFileEventConsumer -Namespace "root\subscription" -Arguments $ArgSet-WmiInstance -Class __FilterToConsumerBinding -Namespace "root\subscription" -Arguments @{Filter=$WMIEventFilter;Consumer=$WMIEventConsumer}
复制代码

监视 “HKEY_LOCAL_MACHINE\\SOFTWARE\Microsoft\Windows\CurrentVersion\Run” 键值的任何改动

如图

(2)监视某一键值及其子键

监视 “HKEY_LOCAL_MACHINE\\SOFTWARE\Microsoft” 键值及其子键的任何改动

$filterName = 'BotFilter52'
$consumerName = 'BotConsumer52'$Query ="SELECT * FROM RegistryTreeChangeEvent WHERE Hive='HKEY_LOCAL_MACHINE' AND RootPath='SOFTWARE\\Microsoft\\'" $WMIEventFilter = Set-WmiInstance -Class __EventFilter -NameSpace "root\subscription" -Arguments @{Name=
$filterName;EventNameSpace="root\default";QueryLanguage="WQL";Query=$Query} -ErrorAction Stop$Arg =@{Name=$consumerNameFilename = 'C:\test\logtree.log'Text ='The change is HKEY_LOCAL_MACHINE\\%RootPath%'}$WMIEventConsumer = Set-WmiInstance -Class LogFileEventConsumer -Namespace "root\subscription" -Arguments $Arg
Set-WmiInstance -Class __FilterToConsumerBinding -Namespace "root\subscription" -Arguments @{Filter=$WMIEventFilter;Consumer=$WMIEventConsumer}
复制代码

0x04 检测工具测试

测试工具：

Sysinternals Autoruns
复制代码

检测目标：

能否查出所有WMI定时运行的操作

测试方法：

在目标主机运行包含以下Consumer的定时运行操作，使用Sysinternals Autoruns进行检测。

-ActiveScriptEventConsumer
-CommandLineEventConsumer
-LogFileEventConsumer
-NTEventLogEventConsumer
-ScriptingStandardConsumerSetting
-SMTPEventConsumer
复制代码

测试结果：

如图

Sysinternals Autoruns只能检测到ActiveScriptEventConsumer和CommandLineEventConsumer的操作，可以理解为上述对进程和注册表监视的操作无法识别

解决措施：

直接查询WMI调用，即可获得所有定时执行的操作

#List Event FiltersGet-WMIObject -Namespace root\Subscription -Class __EventFilter#List Event ConsumersGet-WMIObject -Namespace root\Subscription -Class __EventConsumer#List Event BindingsGet-WMIObject -Namespace root\Subscription -Class __FilterToConsumerBinding
复制代码

0x05 WMI使用补充

以上三篇关于WMI的文章均采用Powershell实现，当然用mof和vbs也能够实现，这里给出一些参考代码，其他功能代码按照格式修改即可

1、mof文件记录注册表修改的操作

（1）以下文件保存为reg.mof文件

 #pragma namespace ("\\\\.\\root\\subscription")instance of __EventFilter as $Filter{Name = "RunKeyFilter";QueryLanguage = "WQL";Query = "Select * from RegistryTreeChangeEvent"" where (Hive = \"HKEY_LOCAL_MACHINE\" and ""KeyPath = \"Software\\\\Microsoft\\\\Windows""\\\\CurrentVersion\\\\Run\")";// RegistryTreeChangeEvents only fire// in root\default namespaceEventNamespace = "root\\default";   };instance of LogFileEventConsumer as $Consumer{Name= "consumer1";Filename = "C:\test\log.log";Text ="The change is HKEY_LOCAL_MACHINE\\%KeyPath%";};// Bind the filter to the consumerinstance of __FilterToConsumerBinding{Filter = $Filter;Consumer = $Consumer;};
复制代码

（2）编译mof文件

命令行下管理员权限执行mofcomp reg.mof

2、vbs文件记录注册表修改的操作

strComputer = "."
Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\default")
Set colEvents = objWMIService.ExecNotificationQuery _("SELECT * FROM RegistryKeyChangeEvent WHERE Hive='HKEY_LOCAL_MACHINE' AND " & _"KeyPath='SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run'")
DoSet objLatestEvent = colEvents.NextEventWscript.Echo Now & ": The registry has been modified."
Loop
复制代码

0x06 小结

以上三篇对WMI Attacks、WMI Backdoor、WMI Defense做了全面介绍，时间有限细节之处难免会有疏忽，欢迎大家共同交流，共同学习，我会在留言作适当补充更正：）

本文由三好学生原创并首发于乌云drops，转载请注明