SMB

SMB (Server Message Block Protocol) is a Client-Server communication Protocol used for Sharing access to Files, Printers, Serial Ports and other resources on a Network.

:: NBT Over IP
139/TCP

:: SMB Over IP
445/TCP

The SMB protocol is known as a Response-Request Protocol, meaning that it transmits multiple messages between the Client and Server to establish a Connection.

Once the Connection is Established, clients can then send Commands to the Server that allow them to access Shares, Open Files, Read and Write Files etc..

Enumeration

:: Simple Enumeration
smbclient --no-pass -L //<IP>

:: Extensive Enumeration
:: -U -G [Users - Group Enumeration]
enum4linux-ng -A <IP>
enum4linux -a <IP>

:: Show Shares && Permissions
smbmap -H <IP>

:: Enumerate Anonymously [Null User]
:: --loggedon-users [Enumerate Logged Users]
crackmapexec smb <IP> -u "" -p "" --shares
crackmapexec smb <IP> --pass-pol -u "" -p ""

Connecting

:: Connecting
smbclient --no-pass //IP/SHARE

:: Null Session Windows Share Connection
smbclient -U '%' -N \\\\IP\\SHARE

:: Recursively List Directories
smbmap -R profiles -H <IP>

:: GUI
xdg-open smb://IP/

:: GUI [Use Nautilus && Browser or Alternatives]
smb://IP/SHARE/

Brute-Force

hydra -l <Username> -P <WordList> smb://<IP>