ntlmrelayx

Impacket's ntlmrelayx is a powerful tool designed to perform NTLM relay attacks. An NTLM relay attack is a type of security vulnerability where an attacker intercepts NTLM (NT LAN Manager) authentication traffic and then relays this traffic to another server to authenticate as the intercepted user. This tool is part of the Impacket suite, a collection of Python classes for working with network protocols.

The primary function of ntlmrelayx is to intercept and relay NTLM authentication requests from one host to another. This allows the attacker to authenticate to a target server with the credentials of a user whose traffic was intercepted. It can relay credentials to various types of services, including SMB, HTTP, and others that support NTLM authentication.

ntlmrelayx can be configured to automatically execute specific actions upon successful relay, such as running commands, dumping hashes, or exploiting known vulnerabilities. Often used in conjunction with other Impacket tools like responder, which can poison network traffic and facilitate the capture of NTLM authentication messages for relay.

Here's an example:

python ntlmrelayx.py -t smb://<TARGET_IP>

• -t smb://<TARGET_IP> specifies the target to relay the NTLM authentication to, using SMB protocol.
• You would typically run this command alongside a tool like Impacket's responder, which induces network clients to send their NTLM authentication messages to you.