Hydra
Hydra is a brute force online pasword cracking program, a quick system login password "hacking" tool. It can run through a list and “brute force” some authentication services. Imagine trying to manually guess someone’s password on a particular service (SSH, Web Application Form, FTP or SNMP) - we can use Hydra to run through a password list and speed this process up for us, determining the correct password.
warning
This shows the importance of using a strong password; if your password is common, doesn’t contain special characters and is not above eight characters, it will be prone to be guessed.
Brute force SSH login
hydra -l <username> -P <full path to pass> <HOST_IP> -t 4 ssh
# -l specifies the SSH username for login
# -P specifies the full path to the password file
# -t 4 specifies the number of parallel tasks to run
hydra -l <username> -P rockyou.txt <HOST_IP> http-post-form "<path>:<login_credentials>:<invalid response>"
# -l specifies the username for login
# -P specifies the password file to use
# http-post-form specifies the HTTP POST form to target
# <path> is the path to the login form on the target web application, e.g. "/login.php"
# <login_credentials> are sent in the format "username=^USER^&password=^PASS^"
# <invalid response> is the text that indicates a failed login attempt, e.g. "Invalid username or password"
Hydra options
-L <userlist> # -L specifies a file containing a list of usernames
-l <username> # -l specifies a single username to use
-P <passlist> # -L specifies a file containing a list of usernames
-p <password> # -p specifies a single password to use
-t <number> # -t specifies the number of parallel tasks to run
-C <user:passlist> # -C specifies a file containing a list of usernames and passwords in the format user:password
-s <port> # -s specifies the port to connect to (if the service is not running on the default port)
-h # -h displays the help message