hydra

Brute force SSH

$ hydra -l [user] -P [passwords.txt] ssh://[target]

$ hydra -l [admin] -P [pass.txt] [target] http-post-form "/login:user=^USER^&pass=^PASS^:Invalid"

$ hydra -L [users.txt] -P [pass.txt] ftp://[target]

$ hydra -t [4] -l [user] -P [pass.txt] [target] [service]

$ hydra -v -l [user] -P [pass.txt] [target] ssh

hydra [options] target service

Hydra is a fast network login cracker supporting many protocols. It performs brute force attacks against remote authentication services.
The tool supports SSH, FTP, HTTP, SMB, databases, and many more protocols. It's used for authorized penetration testing and security auditing.
Hydra brute forces network logins.

TARGET

Target host.

Service to attack (ssh, ftp, http-post-form).

Single username.

Username list.

Single password.

Password list.

Parallel connections.

Verbose output.

Display help information.

Authorized testing only. May trigger lockouts. Use responsibly.

Hydra was developed by THC (The Hacker's Choice) as a comprehensive network authentication testing tool.

ncrack(1), medusa(1), john(1)