Windows Management Instrumentation (WMI) Footprinting

wmiexec.py

#!/usr/bin/env python
# Impacket - Collection of Python classes for working with network protocols.
#
# Copyright (C) 2022 Fortra. 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 smbexec but executing commands through WMI.
#   Main advantage here is it runs under the user (has to be Admin)
#   account, not SYSTEM, plus, it doesn't generate noisy messages
#   in the event log that smbexec.py does when creating a service.
#   Drawback is it needs DCOM, hence, I have to be able to access
#   DCOM ports at the target machine.
#
# Author:
#   beto (@agsolino)
#
# Reference for:
#   DCOM
#

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

from impacket.examples import logger
from impacket.examples.utils import parse_target
from impacket import version
from impacket.smbconnection import SMBConnection, SMB_DIALECT, SMB2_DIALECT_002, SMB2_DIALECT_21
from impacket.dcerpc.v5.dcomrt import DCOMConnection, COMVERSION
from impacket.dcerpc.v5.dcom import wmi
from impacket.dcerpc.v5.dtypes import NULL
from impacket.krb5.keytab import Keytab
from six import PY2

OUTPUT_FILENAME = '__' + str(time.time())
CODEC = sys.stdout.encoding


class WMIEXEC:
    def __init__(self, command='', username='', password='', domain='', hashes=None, aesKey=None, share=None,
                 noOutput=False, doKerberos=False, kdcHost=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.__shell_type = shell_type
        self.shell = None
        if hashes is not None:
            self.__lmhash, self.__nthash = hashes.split(':')

    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:
            iInterface = dcom.CoCreateInstanceEx(wmi.CLSID_WbemLevel1Login, wmi.IID_IWbemLevel1Login)
            iWbemLevel1Login = wmi.IWbemLevel1Login(iInterface)
            iWbemServices = iWbemLevel1Login.NTLMLogin('//./root/cimv2', NULL, NULL)
            iWbemLevel1Login.RemRelease()

            win32Process, _ = iWbemServices.GetObject('Win32_Process')

            self.shell = RemoteShell(self.__share, win32Process, smbConnection, self.__shell_type, silentCommand)
            if self.__command != ' ':
                self.shell.onecmd(self.__command)
            else:
                self.shell.cmdloop()
        except  (Exception, KeyboardInterrupt) as e:
            if logging.getLogger().level == logging.DEBUG:
                import traceback
                traceback.print_exc()
            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, win32Process, smbConnection, shell_type, silentCommand=False):
        cmd.Cmd.__init__(self)
        self.__share = share
        self.__output = '\\' + OUTPUT_FILENAME
        self.__outputBuffer = str('')
        self.__shell = 'cmd.exe /Q /c '
        self.__shell_type = shell_type
        self.__pwsh = 'powershell.exe -NoP -NoL -sta -NonI -W Hidden -Exec Bypass -Enc '
        self.__win32Process = win32Process
        self.__transferClient = smbConnection
        self.__silentCommand = silentCommand
        self.__pwd = str('C:\\')
        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

        # If the user wants to just execute a command without cmd.exe, set raw command and set no output
        if self.__silentCommand is True:
            self.__shell = ''

    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))

            if os.path.exists(filename):
                os.remove(filename)

    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):
        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 + '>')
                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 wmiexec.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 shell_type == 'powershell':
            data = '$ProgressPreference="SilentlyContinue";' + data
            data = self.__pwsh + b64encode(data.encode('utf-16le')).decode()

        command = self.__shell + data

        if self.__noOutput is False:
            command += ' 1> ' + '\\\\127.0.0.1\\%s' % self.__share + self.__output + ' 2>&1'
        if PY2:
            self.__win32Process.Create(command.decode(sys.stdin.encoding), self.__pwd, None)
        else:
            self.__win32Process.Create(command, self.__pwd, None)
        self.get_output()

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


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 Windows "
                                                                "Management Instrumentation.")
    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('-silentcommand', action='store_true', default=False,
                        help='does not execute cmd.exe to run given command (no 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('-shell-type', action='store', default='cmd', choices=['cmd', 'powershell'],
                        help='choose a command processor for the semi-interactive shell')
    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('command', nargs='*', default=' ', help='command to execute at the target. If empty it will '
                                                                'launch a semi-interactive shell')

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

            traceback.print_exc()
        logging.error(str(e))
        sys.exit(1)

    sys.exit(0)