☑️Windows Remote Management Protocols - 3389,5985,5986,135
Windows Remote Management protocols are enabled by default on Windows Server 2016 and onwards. Remote management is a component of the Windows hardware management features that manage server hardware locally and remotely. These features include a service that implements the WS-Management protocol, hardware diagnostics and control through baseboard management controllers, and a COM API and script objects that enable us to write applications that communicate remotely through the WS-Management protocol.
The main components used for remote management of Windows and Windows servers are the following:
Remote Desktop Protocol (RDP)
Windows Remote Management (WinRM)
Windows Management Instrumentation (WMI)
RDP
RDP uses Port 3389 and GUI to manage Windows systems encrypted over a network at the application layer. . If Network Address Translation (NAT) is used on the route between client and server, as is often the case with Internet connections, the remote computer needs the public IP address to reach the server. In addition, port forwarding must be set up on the NAT router in the direction of the server.
RDP has handled Transport Layer Security (TLS/SSL) since Windows Vista, which means that all data, and especially the login process, is protected in the network by its good encryption. However, many Windows systems do not insist on this but still accept inadequate encryption via RDP Security. Nevertheless, even with this, an attacker is still far from being locked out because the identity-providing certificates are merely self-signed by default. This means that the client cannot distinguish a genuine certificate from a forged one and generates a certificate warning for the user.
Footprinting RDP
Scanning the RDP service can quickly give us a lot of information about the host. For example, we can determine if NLA is enabled on the server or not, the product version, and the hostname.
anonmak9@htb[/htb]$ nmap -sV -sC 10.129.201.248 -p3389 --script rdp*
Starting Nmap 7.92 ( https://nmap.org ) at 2021-11-06 15:45 CET
Nmap scan report for 10.129.201.248
Host is up (0.036s latency).
PORT STATE SERVICE VERSION
3389/tcp open ms-wbt-server Microsoft Terminal Services
| rdp-enum-encryption:
| Security layer
| CredSSP (NLA): SUCCESS
| CredSSP with Early User Auth: SUCCESS
|_ RDSTLS: SUCCESS
| rdp-ntlm-info:
| Target_Name: ILF-SQL-01
| NetBIOS_Domain_Name: ILF-SQL-01
| NetBIOS_Computer_Name: ILF-SQL-01
| DNS_Domain_Name: ILF-SQL-01
| DNS_Computer_Name: ILF-SQL-01
| Product_Version: 10.0.17763
|_ System_Time: 2021-11-06T13:46:00+00:00
Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 8.26 secondsIn addition, we can use --packet-trace to track the individual packages and inspect their contents manually. We can see that the RDP cookies (mstshash=nmap) used by Nmap to interact with the RDP server can be identified by threat hunters and various security services such as Endpoint Detection and Response (EDR), and can lock us out as penetration testers on hardened networks.
A Perl script named rdp-sec-check.pl has also been developed by Cisco CX Security Labs that can unauthentically identify the security settings of RDP servers based on the handshakes.
Installation
RDP Security Check
Initiating RDP sessions
Authentication and connection to such RDP servers can be made in several ways. For example, we can connect to RDP servers on Linux using xfreerdp, rdesktop, or Remmina and interact with the GUI of the server accordingly.
WinRM
The Windows Remote Management (WinRM) is a simple Windows integrated remote management protocol based on the command line. WinRM uses the Simple Object Access Protocol (SOAP) to establish connections to remote hosts and their applications. Therefore, WinRM must be explicitly enabled (unlike RDP) and configured starting with Windows 10.
WinRM relies on TCP ports 5985 and 5986 for communication, with the last port 5986 using HTTPS, as ports 80 and 443 were previously used for this task. However, since port 80 was mainly blocked for security reasons, the newer ports 5985 and 5986 are used today.
Another component that fits WinRM for administration is Windows Remote Shell (WinRS), which lets us execute arbitrary commands on the remote system. The program is even included on Windows 7 by default. Thus, with WinRM, it is possible to execute a remote command on another server.
Note: Services like remote sessions using PowerShell and event log merging require WinRM.
It is enabled by default starting with the Windows Server 2012 version, but it must first be configured for older server versions and clients, and the necessary firewall exceptions created.
Footprinting WinRM
If we want to find out whether one or more remote servers can be reached via WinRM, we can easily do this with the help of PowerShell. The Test-WsMan cmdlet is responsible for this, and the host's name in question is passed to it.
In Linux-based environments, we can use the tool called evil-winrm, another penetration testing tool designed to interact with WinRM.
WMI
Windows Management Instrumentation (WMI) is Microsoft's implementation and also an extension of the Common Information Model (CIM), core functionality of the standardized Web-Based Enterprise Management (WBEM) for the Windows platform. WMI allows read and write access to almost all settings on Windows systems. Understandably, this makes it the most critical interface in the Windows environment for the administration and remote maintenance of Windows computers, regardless of whether they are PCs or servers
WMI is typically accessed via PowerShell, VBScript, or the Windows Management Instrumentation Console (WMIC). WMI is not a single program but consists of several programs and various databases, also known as repositories.
Footprinting WMI
The initialization of the WMI communication always takes place on TCP port 135, and after the successful establishment of the connection, the communication is moved to a random port.
Using wmiexec.py
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