ntlmrelayx.py SOCKS option TypeError with socks5

[mpgn]

Configuration

impacket version: Impacket v0.9.23.dev1+20201123.132651.18df2123
Python version: 3.8
Target OS: Windows

Debug Output With Command String

When using socks option from ntlmrelayx.py, there is an error when trying to use secredump or any other tool with proxychains.

sudo ntlmrelayx.py -tf /tmp/relay.txt -smb2support -socks

...


ntlmrelayx> socks
Protocol  Target           Username                AdminStatus  Port 
--------  ---------------  ----------------------  -----------  ----
SMB       192.168.133.164  POUDLARD/ADMINISTRATOR  TRUE         445  
ntlmrelayx> 
ntlmrelayx> 
ntlmrelayx> 
ntlmrelayx> ----------------------------------------
Exception happened during processing of request from ('192.168.133.156', 39640)
Traceback (most recent call last):
  File "/usr/lib/python3.8/socketserver.py", line 650, in process_request_thread
    self.finish_request(request, client_address)
  File "/usr/lib/python3.8/socketserver.py", line 360, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/usr/local/lib/python3.8/dist-packages/impacket-0.9.23.dev1+20201123.132651.18df2123-py3.8.egg/impacket/examples/ntlmrelayx/servers/socksserver.py", line 283, in __init__
    socketserver.BaseRequestHandler.__init__(self, request, client_address, server)
  File "/usr/lib/python3.8/socketserver.py", line 720, in __init__
    self.handle()
  File "/usr/local/lib/python3.8/dist-packages/impacket-0.9.23.dev1+20201123.132651.18df2123-py3.8.egg/impacket/examples/ntlmrelayx/servers/socksserver.py", line 305, in handle
    self.__connSocket.sendall(str(SOCKS5_GREETINGS_BACK()))
TypeError: __str__ returned non-string (type bytes)
----------------------------------------

I got this error when using proxychains:

$ proxychains secretsdump.py POUDLARD/[email protected] -no-pass
[proxychains] config file found: /etc/proxychains4.conf
[proxychains] preloading /usr/lib/x86_64-linux-gnu/libproxychains.so.4
[proxychains] DLL init: proxychains-ng 4.14
Impacket v0.9.23.dev1+20201123.132651.18df2123 - Copyright 2020 SecureAuth Corporation

[proxychains] Strict chain  ...  192.168.133.156:1080  ...  192.168.133.164:445 <--socket error or timeout!
[-] RemoteOperations failed: [Errno Connection error (192.168.133.164:445)] [Errno 111] Connection refused
[*] Cleaning up... 

$ nmap -v -p 445 192.168.133.164                                                                                                                                                                          130 ⨯
Starting Nmap 7.91 ( https://nmap.org ) at 2021-01-27 09:59 EST
Initiating Ping Scan at 09:59
Scanning 192.168.133.164 [2 ports]
Completed Ping Scan at 09:59, 0.00s elapsed (1 total hosts)
Initiating Parallel DNS resolution of 1 host. at 09:59
Completed Parallel DNS resolution of 1 host. at 09:59, 0.02s elapsed
Initiating Connect Scan at 09:59
Scanning 192.168.133.164 [1 port]
Discovered open port 445/tcp on 192.168.133.164
Completed Connect Scan at 09:59, 0.00s elapsed (1 total ports)
Nmap scan report for 192.168.133.164
Host is up (0.00065s latency).

PORT    STATE SERVICE
445/tcp open  microsoft-ds

Read data files from: /usr/bin/../share/nmap
Nmap done: 1 IP address (1 host up) scanned in 0.07 seconds

PCAP

no pcap

Additional context

fail when using socks option from ntlmrelayx using socks5 in proxychains but it works using socks4

[asolino]

Thanks for the report @mpgn. I can reproduce it.
In the meantime switch to socks4 in your proxychains.conf. It should work with that version.

[mpgn]

Yep, using socks4 it's working fine 👍

[asolino]

Please git pull and retest @mpgn

[mpgn]

can confirm it's working with socks5 💯