NetExec/cme/modules/spider_plus.py

331 lines
12 KiB
Python
Executable File

import json
import errno
import os
import time
import logging
import traceback
from cme.protocols.smb.remotefile import RemoteFile
from impacket import smb
from impacket.smb3structs import FILE_READ_DATA
from impacket.smbconnection import SessionError
CHUNK_SIZE = 4096
suffixes = ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB']
def humansize(nbytes):
i = 0
while nbytes >= 1024 and i < len(suffixes)-1:
nbytes /= 1024.
i += 1
f = ('%.2f' % nbytes).rstrip('0').rstrip('.')
return '%s %s' % (f, suffixes[i])
def humaclock(time):
return time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(time))
def make_dirs(path):
"""
Create the directory structure. We handle an exception `os.errno.EEXIST` that
may occured while the OS is creating the directories.
"""
try:
os.makedirs(path)
except OSError as e:
if e.errno != errno.EEXIST:
raise
pass
get_list_from_option = lambda opt: list(map(lambda o: o.lower(), filter(bool, opt.split(','))))
class SMBSpiderPlus:
def __init__(self, smb, logger, read_only, exclude_dirs, exclude_exts, max_file_size, output_folder):
self.smb = smb
self.host = self.smb.conn.getRemoteHost()
self.conn_retry = 5
self.logger = logger
self.results = {}
self.read_only = read_only
self.exclude_dirs = exclude_dirs
self.exclude_exts = exclude_exts
self.max_file_size = max_file_size
self.output_folder = output_folder
# Make sure the output_folder exists
make_dirs(self.output_folder)
def reconnect(self):
if self.conn_retry > 0:
self.conn_retry -= 1
self.logger.info(f"Reconnect to server {self.conn_retry}")
# Renogociate the session
time.sleep(3)
self.smb.create_conn_obj()
self.smb.login()
return True
return False
def list_path(self, share, subfolder):
filelist = []
try:
# Get file list for the current folder
filelist = self.smb.conn.listPath(share, subfolder + '*')
except SessionError as e:
self.logger.debug(f'Failed listing files on share "{share}" in directory {subfolder}.')
self.logger.debug(str(e))
if 'STATUS_ACCESS_DENIED' in str(e):
self.logger.debug(f"Cannot list files in directory \"{subfolder}\"")
elif 'STATUS_OBJECT_PATH_NOT_FOUND' in str(e):
self.logger.debug(f"The directory {subfolder} does not exist.")
elif self.reconnect():
filelist = self.list_path(share, subfolder)
return filelist
def get_remote_file(self, share, path):
try:
remote_file = RemoteFile(self.smb.conn, path, share, access=FILE_READ_DATA)
return remote_file
except SessionError:
if self.reconnect():
return self.get_remote_file(share, path)
return None
def read_chunk(self, remote_file, chunk_size=CHUNK_SIZE):
"""
Read the next chunk of data from the remote file.
We retry 3 times if there is a SessionError that is not a `STATUS_END_OF_FILE`.
"""
chunk = ''
retry = 3
while retry > 0:
retry -= 1
try:
chunk = remote_file.read(chunk_size)
break
except SessionError:
if self.reconnect():
# Little hack to reset the smb connection instance
remote_file.__smbConnection = self.smb.conn
return self.read_chunk(remote_file)
except Exception:
traceback.print_exc()
break
return chunk
def spider(self):
self.logger.debug("Enumerating shares for spidering")
shares = self.smb.shares()
try:
# Get all available shares for the SMB connection
for share in shares:
perms = share['access']
name = share['name']
self.logger.debug(f"Share \"{name}\" has perms {perms}")
# We only want to spider readable shares
if not 'READ' in perms:
continue
# `exclude_dirs` is applied to the shares name
if name.lower() in self.exclude_dirs:
self.logger.debug(f"Share \"{name}\" has been excluded.")
continue
try:
# Start the spider at the root of the share folder
self.results[name] = {}
self._spider(name, '')
except SessionError:
traceback.print_exc()
self.logger.error(f"Got a session error while spidering")
self.reconnect()
except Exception as e:
traceback.print_exc()
self.logger.error(f"Error enumerating shares: {str(e)}")
# Save the server shares metadatas if we want to grep on filenames
self.dump_folder_metadata(self.results)
return self.results
def _spider(self, share, subfolder):
self.logger.debug(f'Spider share "{share}" on folder "{subfolder}"')
filelist = self.list_path(share, subfolder + '*')
if share.lower() in self.exclude_dirs:
self.logger.debug(f'The directory has been excluded')
return
# For each entry:
# - It's a directory then we spider it (skipping `.` and `..`)
# - It's a file then we apply the checks
for result in filelist:
next_path = subfolder + result.get_longname()
next_path_lower = next_path.lower()
self.logger.debug(f'Current file on share "{share}": {next_path}')
# Exclude the current result if it's in the exlude_dirs list
if any(map(lambda d: d in next_path_lower, self.exclude_dirs)):
self.logger.debug(f'The path "{next_path}" has been excluded')
continue
if result.is_directory():
if result.get_longname() in ['.', '..']:
continue
self._spider(share, next_path + '/')
else:
# Record the file metadata
self.results[share][next_path] = {
'size': humansize(result.get_filesize()),
#'ctime': time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(result.get_ctime())),
'ctime_epoch': time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(result.get_ctime_epoch())),
#'mtime': time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(result.get_mtime())),
'mtime_epoch': time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(result.get_mtime_epoch())),
#'atime': time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(result.get_atime())),
'atime_epoch': time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(result.get_atime_epoch()))
}
# The collection logic is here. You can add more checks based
# on the file size, content, name, date...
# Check the file extension. We check here to prevent the creation
# of a RemoteFile object that perform a remote connection.
file_extension = next_path[next_path.rfind('.')+1:]
if file_extension in self.exclude_exts:
self.logger.debug(f'The file "{next_path}" has an excluded extension')
continue
# If there is not results in the file but the size is correct,
# then we save it
if result.get_filesize() > self.max_file_size:
self.logger.debug(f'File {result.get_longname()} has size {result.get_filesize()}')
continue
## You can add more checks here: date, ...
if self.read_only == True:
continue
# The file passes the checks, then we fetch it!
remote_file = self.get_remote_file(share, next_path)
if not remote_file:
self.logger.error(f'Cannot open remote file "{next_path}".')
continue
try:
remote_file.open()
## TODO: add checks on the file content here
self.save_file(remote_file)
remote_file.close()
except SessionError as e:
if 'STATUS_SHARING_VIOLATION' in str(e):
pass
except Exception as e:
traceback.print_exc()
self.logger.error(f'Error reading file {next_path}: {str(e)}')
def save_file(self, remote_file):
# Reset the remote_file to point to the begining of the file
remote_file.seek(0, 0)
# remove the "\\" before the remote host part
file_path = str(remote_file)[2:]
# The remote_file.file_name contains '/'
file_path = file_path.replace('/', os.path.sep)
file_path = file_path.replace('\\', os.path.sep)
filename = file_path.split(os.path.sep)[-1]
directory = os.path.join(self.output_folder, file_path[:-len(filename)])
# Create the subdirectories based on the share name and file path
self.logger.debug(f'Create directory "{directory}"')
make_dirs(directory)
with open(os.path.join(directory, filename), 'wb') as fd:
while True:
chunk = self.read_chunk(remote_file)
if not chunk:
break
fd.write(chunk)
def dump_folder_metadata(self, results):
# Save the remote host shares metadatas to a json file
# TODO: use the json file as an input to save only the new or modified
# files since the last time.
path = os.path.join(self.output_folder, f'{self.host}.json')
with open(path, 'w', encoding='utf-8') as fd:
fd.write(json.dumps(results, indent=4, sort_keys=True))
class CMEModule:
'''
Spider plus module
Module by @vincd
'''
name = 'spider_plus'
description = 'List files on the target server (excluding `DIR` directories and `EXT` extensions) and save them to the `OUTPUT` directory if they are smaller then `SIZE`'
supported_protocols = ['smb']
opsec_safe= True # Does the module touch disk?
multiple_hosts = True # Does it make sense to run this module on multiple hosts at a time?
def options(self, context, module_options):
"""
READ_ONLY Only list files and put the name into a JSON (default: True)
EXCLUDE_EXTS Extension file to exclude (Default: ico,lnk)
EXCLUDE_DIR Directory to exclude (Default: print$)
MAX_FILE_SIZE Max file size allowed to dump (Default: 51200)
OUTPUT_FOLDER Path of the remote folder where the dump will occur (Default: /tmp/cme_spider_plus)
"""
self.read_only = module_options.get('READ_ONLY', True)
self.exclude_exts = get_list_from_option(module_options.get('EXCLUDE_EXTS', 'ico,lnk'))
self.exlude_dirs = get_list_from_option(module_options.get('EXCLUDE_DIR', 'print$'))
self.max_file_size = int(module_options.get('SIZE', 50 * 1024))
self.output_folder = module_options.get('OUTPUT', os.path.join('/tmp', 'cme_spider_plus'))
def on_login(self, context, connection):
context.log.info('Started spidering plus with option:')
context.log.info(' DIR: {dir}'.format(dir=self.exlude_dirs))
context.log.info(' EXT: {ext}'.format(ext=self.exclude_exts))
context.log.info(' SIZE: {size}'.format(size=self.max_file_size))
context.log.info(' OUTPUT: {output}'.format(output=self.output_folder))
spider = SMBSpiderPlus(
connection,
context.log,
self.read_only,
self.exlude_dirs,
self.exclude_exts,
self.max_file_size,
self.output_folder,
)
spider.spider()