Metasploit modules

auxiliary/scanner/smb/smb_login
auxiliary/scanner/smb/pipe_auditor
exploit/multi/samba/usermap_script

Hydra

hydra -l admin -P /usr/share/wordlists/rockyou.txt 192.212.251.3 smb
gzip -d /usr/share/wordlists/rockyou.txt.gz

smbmap

smbmap -H 192.212.251.3 -u admin -p password1
smbclient -L 192.212.251.3 -U jane : list shares on samba server
smbclient //192.212.251.3/jane -U jane : check if jane share exists
enum4linux -r -u "admin" -p "password1" 192.212.251.3 : get SID

Refer to Info Gathering & Enum > smb for more commands