Exception when scanning responder host using SMB

[denevin]

Describe the bug When doing SMB scan against a host which is running responder SMB server, netexec generates an exception each time.

To Reproduce Run responder Command: responder -I eth0

Run netexec against subnet, including a host running responder. Command: nxc smb 192.168.1.0/24 Resulted in:

Running nxc against 254 targets ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 100% 0:00:00
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/nxc/connection.py", line 166, in __init__
    self.proto_flow()
    ~~~~~~~~~~~~~~~^^
  File "/usr/lib/python3/dist-packages/nxc/connection.py", line 231, in proto_flow
    self.enum_host_info()
    ~~~~~~~~~~~~~~~~~~~^^
  File "/usr/lib/python3/dist-packages/nxc/protocols/smb.py", line 261, in enum_host_info
    if "Windows 6.1" in self.server_os and self.server_os_build == 0 and self.os_arch == 0:
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: a bytes-like object is required, not 'str'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/nxc/netexec.py", line 64, in start_run
    future.result()
    ~~~~~~~~~~~~~^^
  File "/usr/lib/python3.13/concurrent/futures/_base.py", line 449, in result
    return self.__get_result()
           ~~~~~~~~~~~~~~~~~^^
  File "/usr/lib/python3.13/concurrent/futures/_base.py", line 401, in __get_result
    raise self._exception
  File "/usr/lib/python3.13/concurrent/futures/thread.py", line 59, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/lib/python3/dist-packages/nxc/protocols/smb.py", line 170, in __init__
    connection.__init__(self, args, db, host)
    ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/nxc/connection.py", line 174, in __init__
    self.logger.exception(f"Exception while calling proto_flow() on target {target}: {e}")
    ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/logging/__init__.py", line 1929, in exception
    self.log(ERROR, msg, *args, exc_info=exc_info, **kwargs)
    ~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/logging/__init__.py", line 1943, in log
    msg, kwargs = self.process(msg, kwargs)
                  ~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/usr/lib/python3.13/logging/__init__.py", line 1887, in process
    if self.merge_extra and "extra" in kwargs:
       ^^^^^^^^^^^^^^^^
AttributeError: 'NXCAdapter' object has no attribute 'merge_extra'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/bin/nxc", line 8, in <module>
    sys.exit(main())
             ~~~~^^
  File "/usr/lib/python3/dist-packages/nxc/netexec.py", line 222, in main
    asyncio.run(start_run(protocol_object, args, db, targets))
    ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/asyncio/runners.py", line 195, in run
    return runner.run(main)
           ~~~~~~~~~~^^^^^^
  File "/usr/lib/python3.13/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "/usr/lib/python3.13/asyncio/base_events.py", line 719, in run_until_complete
    return future.result()
           ~~~~~~~~~~~~~^^
  File "/usr/lib/python3/dist-packages/nxc/netexec.py", line 66, in start_run
    nxc_logger.exception(f"Exception for target {targets[futures.index(future)]}: {future.exception()}")
    ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/logging/__init__.py", line 1929, in exception
    self.log(ERROR, msg, *args, exc_info=exc_info, **kwargs)
    ~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/logging/__init__.py", line 1943, in log
    msg, kwargs = self.process(msg, kwargs)
                  ~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/usr/lib/python3.13/logging/__init__.py", line 1887, in process
    if self.merge_extra and "extra" in kwargs:
       ^^^^^^^^^^^^^^^^
AttributeError: 'NXCAdapter' object has no attribute 'merge_extra'
...

Expected behavior Do not generate an exception error when running SMB scan against host running SMB server using responder.

NetExec info

• OS: Kali
• Version of nxc: 1.3.0
• Installed from: apt

[NeffIsBack]

Hi and thanks for the bug report. This has already been fixed since the last release. Until a new release is out you can install NetExec with pipx so you get the latest bug fixes