Hydra can launch attacks on multiple targets at once using threads, called hydra heads. The tool keeps track of the threads using another structure, the hydra brain. Each target is attacked using a module that corresponds to a protocol(eg. if the target is an SSH server, the SSH module is used).
Hydra supports many common login protocols like forms on websites, FTP, SMB, POP3, IMAP, MySQL, VNC, SSH, HTTP(S) and others.4
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