Hydra is a multi-protocol, parallelized authentication brute forcer.

By assigning many parallel tasks, remote login brute forcing can be
accelerated SIGNIFICANTLY, however it depends on the protocol.  
The fastest is generally POP3, then FTP, then Telnet, and the least
IMAP.

Experiment with the task option (-t) to speed things up. The higher, 
the faster (but too high, and it disables the service). To prevent 
disabling you can now use the -g option for "slow-starts".

The following protocols are supported:
Cisco[-enable] (including AAA), FTP, HTTP[S], ICQ, IMAP, LDAP, NNTP,
PCNFS, POP3, REXEC, SMB, SMBNT, SOCKS5, TELNET, MySQL, Socks5 and VNC.
A generic SSL wrapper can also be used in conjuction with the other
protocols.