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A PoC script to capture relevant .NET runtime artifacts for the purposes of potential detections
logman --% start dotNetTrace -p Microsoft-Windows-DotNETRuntime (JitKeyword,NGenKeyword,InteropKeyword,LoaderKeyword) win:Informational -o dotNetTrace.etl -ets
# Do your evil .NET thing now. In this example, I executed the Microsoft.Workflow.Compiler.exe bypass
# logman stop dotNetTrace -ets
# This is the process ID of the process I want to capture. In this case, Microsoft.Workflow.Compiler.exe
# I got the process ID by running a procmon trace
$TargetProcessId = 8256
$WorkflowCompilerEvents = Get-WinEvent -Path .\dotNetTrace.etl -Oldest -FilterXPath "*[System[Execution[@ProcessID=$TargetProcessId]]]"
# Group events by event ID
$EventIDGrouping = $WorkflowCompilerEvents | Sort Id | Group Id
# Event ID 143 corresponds to the following ETW provider keyword: JitKeyword, NGenKeyword
$MethodLoadVerboseEvents = $EventIDGrouping | ? { $_.Name -eq '143' }
$MethodsCalled = $MethodLoadVerboseEvents.Group | % {
$Namespace = $_.Properties[6].Value
$Method = $_.Properties[7].Value
$MethodComponent0 = $_.Properties[8].Value.Split('(')[0].TrimEnd()
$MethodComponent1 = $_.Properties[8].Value.Split('(')[1]
"$($MethodComponent0) $($Namespace)$($Method)($($MethodComponent1)"
}
# Event ID 88 corresponds to the following ETW provider keyword: InteropKeyword
$ILStubStubGeneratedEvents = $EventIDGrouping | ? { $_.Name -eq '88' }
$MarshaledNativeMethods = $ILStubStubGeneratedEvents.Group | % {
$Namespace = $_.Properties[5].Value
$Method = $_.Properties[6].Value
$ReturnVal = $_.Properties[7].Value.Split('(')[0].TrimEnd()
$Signature = $_.Properties[7].Value.Split('(')[1]
"$($ReturnVal) $($Namespace).$($Method)($($Signature)"
}
# Event ID 151 corresponds to the following ETW provider keyword: LoaderKeyword
$LoaderDomainModuleLoadEvents = $EventIDGrouping | ? { $_.Name -eq '151' }
$ModuleLoads = $LoaderDomainModuleLoadEvents.Group | % {
$_.Properties[5].Value
}
# Event ID 154 corresponds to the following ETW provider keyword: LoaderKeyword
$LoaderAssemblyLoadEvents = $EventIDGrouping | ? { $_.Name -eq '154' }
$AssemblyLoads = $LoaderAssemblyLoadEvents.Group | % {
$_.Properties[4].Value
}
# Event ID 157 corresponds to the following ETW provider keyword: LoaderKeyword
$LoaderAppDomainUnloadEvents = $EventIDGrouping | ? { $_.Name -eq '157' }
$AppDomainUnloadLoads = $LoaderAppDomainUnloadEvents.Group | % {
$_.Properties[2].Value
}
# Event ID 187 corresponds to the following ETW provider keyword: LoaderKeyword
$RuntimeStartEvents = $EventIDGrouping | ? { $_.Name -eq '187' }
$CommandLines = $RuntimeStartEvents.Group | % {
$_.Properties[12].Value
}
$DotNetEvents = [PSCustomObject] @{
ProcessID = $TargetProcessId
CommandLine = $CommandLines
AppDomainsLoaded = $AppDomainUnloadLoads
AssembliesLoaded = $AssemblyLoads
ModulesLoaded = $ModuleLoads
ManagedMethodsCalled = $MethodsCalled
PInvokeMethodsCalled = $MarshaledNativeMethods
}
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