• Definition: An NTLM hash is a cryptographic representation of a password used by the NT LAN Manager (NTLM) authentication protocol in Microsoft Windows systems. It is derived from the user's password and is used for authentication without transmitting the actual password over the network.
• Function: Converts a user's password into a fixed-length string using the MD4 hashing algorithm, which is then stored and used for verifying user credentials.
• Components:
  • User Password: The original password input by the user.
  • MD4 Hashing Algorithm: The cryptographic algorithm used to create the NTLM hash from the user password.
  • NTLM Hash String: The resulting fixed-length string that represents the hashed password.
• Features:
  • Fixed-Length Output: The NTLM hash is always a 32-character hexadecimal string regardless of the input password length.
  • No Salt: Unlike many modern hashing algorithms, NTLM hashes do not use a salt, making them more vulnerable to certain types of attacks.
  • Fast Computation: The MD4 algorithm used in NTLM hashing is designed for fast computation, which can be a security weakness.

• Usage: Used in legacy systems and environments where NTLM authentication is required, such as older versions of Windows and certain network configurations.

• Creating an NTLM hash:

   1. Convert the password to Unicode.
   2. Hash the Unicode password using the MD4 algorithm.
   3. The resulting hash is the NTLM hash.

 For example, the NTLM hash of the password "Password123" is:
 ```plaintext
 b4b9b02e6f09a9bd760f388b67351e2b
 ```

• Viewing stored NTLM hashes:

   * NTLM hashes are typically stored in the Security Accounts Manager (SAM) database and can be viewed using specialized tools, often requiring administrative privileges.

• Example of an NTLM hash representation:

   ```plaintext
   Username: John
   Password: Password123
   NTLM Hash: b4b9b02e6f09a9bd760f388b67351e2b
   ```

• Tools for managing NTLM hashes:
  • `hashcat`: A popular password recovery tool that can crack NTLM hashes.
  • `pwdump`: A tool that extracts password hashes (including NTLM) from the SAM database.

• NTLM Hash: A cryptographic representation of a password used by the NTLM authentication protocol in Windows systems, created using the MD4 hashing algorithm. NTLM hashes are fixed-length strings that do not use salts, making them vulnerable to certain attacks. They are used in legacy systems and specific network configurations requiring NTLM authentication.