WMI Defense – 三好学生

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.

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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
$Arg [email protected]{
Name=$consumerName
Filename = 'C:\test\log.log'
Text = 'New Process Created with name %TargetInstance.Name%'
}
$WMIEventConsumer = Set-WmiInstance -Class LogFileEventConsumer -Namespace "root\subscription" -Arguments $Arg
Set-WmiInstance -Class __FilterToConsumerBinding -Namespace "root\subscription" -Arguments @{Filter=$WMIEventFilter;Consumer=$WMIEventConsumer}

如图

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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
$Arg [email protected]{
Name=$consumerName
Filename = 'C:\test\log.log'
Text = 'Task kill with name %TargetInstance.Name%'
}
$WMIEventConsumer = Set-WmiInstance -Class LogFileEventConsumer -Namespace "root\subscription" -Arguments $Arg
Set-WmiInstance -Class __FilterToConsumerBinding -Namespace "root\subscription" -Arguments @{Filter=$WMIEventFilter;Consumer=$WMIEventConsumer}

如图

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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
$Arg [email protected]{
Name=$consumerName
Filename = 'C:\test\log.log'
Text ='The change is HKEY_LOCAL_MACHINE\\%KeyPath%'
}
$WMIEventConsumer = Set-WmiInstance -Class LogFileEventConsumer -Namespace "root\subscription" -Arguments $Arg
Set-WmiInstance -Class __FilterToConsumerBinding -Namespace "root\subscription" -Arguments @{Filter=$WMIEventFilter;Consumer=$WMIEventConsumer}

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

如图

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(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
$Arg [email protected]{
Name=$consumerName
Filename = '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}

0x04 检测工具测试

测试工具

Sysinternals Autoruns

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

测试结果

如图

enter image description here

Sysinternals Autoruns只能检测到ActiveScriptEventConsumerCommandLineEventConsumer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 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

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mofvbs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 namespace
EventNamespace = "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 consumer
instance of __FilterToConsumerBinding
{
Filter = $Filter;
Consumer = $Consumer;
};

(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'") 
Do
Set objLatestEvent = colEvents.NextEvent
Wscript.Echo Now & ": The registry has been modified."
Loop

0x06 小结

以上三篇对WMI AttacksWMI BackdoorWMI 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

原文链接:http://drops.wooyun.org/tips/8290

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