THC Hydra 5.4

THC-Hydra is a very fast network logon cracker which uses a dictionary attack to test for weak or simple passwords on remote hosts running a variety of different services. It was designed as a proof-of-concept utility to demonstrate the ease of cracking poorly chosen passwords.

Hydra supports a wide variety of services:

Samba
FTP
POP3
IMAP
Telnet
HTTP Auth
LDAP
NNTP
MySQL
VNC
Socks5
Cisco
and more

Download THC Hydra here:
THC Hydra 5.4 (all UNIX based platforms)

THC Hydra 5.4(windows port)

You can read more about THC Hydra here.