# -*- coding: utf-8 -*-
"""Windows Registry plugin to parse the BagMRU (or ShellBags) key."""
import os
from dtfabric.runtime import data_maps as dtfabric_data_maps
from plaso.containers import events
from plaso.lib import dtfabric_helper
from plaso.lib import errors
from plaso.parsers.shared import shell_items
from plaso.parsers import winreg_parser
from plaso.parsers.winreg_plugins import interface
[docs]
class BagMRUEventData(events.EventData):
"""BagMRU (or ShellBags) event data attribute container.
Attributes:
entries (str): most recently used (MRU) entries.
key_path (str): Windows Registry key path.
last_written_time (dfdatetime.DateTimeValues): entry last written date and
time.
"""
DATA_TYPE = 'windows:registry:bagmru'
[docs]
def __init__(self):
"""Initializes event data."""
super(BagMRUEventData, self).__init__(data_type=self.DATA_TYPE)
self.entries = None
self.key_path = None
self.last_written_time = None
[docs]
class BagMRUWindowsRegistryPlugin(
interface.WindowsRegistryPlugin, dtfabric_helper.DtFabricHelper):
"""Windows Registry plugin to parse the BagMRU (or ShellBags) key."""
NAME = 'bagmru'
DATA_FORMAT = 'BagMRU (or ShellBags) Registry data'
FILTERS = frozenset([
interface.WindowsRegistryKeyPathFilter(
'HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\Shell\\BagMRU'),
interface.WindowsRegistryKeyPathFilter(
'HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\ShellNoRoam\\'
'BagMRU'),
interface.WindowsRegistryKeyPathFilter(
'HKEY_CURRENT_USER\\Software\\Classes\\Local Settings\\Software\\'
'Microsoft\\Windows\\Shell\\BagMRU'),
interface.WindowsRegistryKeyPathFilter(
'HKEY_CURRENT_USER\\Software\\Classes\\Local Settings\\Software\\'
'Microsoft\\Windows\\ShellNoRoam\\BagMRU'),
interface.WindowsRegistryKeyPathFilter(
'HKEY_CURRENT_USER\\Local Settings\\Software\\Microsoft\\Windows\\'
'Shell\\BagMRU'),
interface.WindowsRegistryKeyPathFilter(
'HKEY_CURRENT_USER\\Local Settings\\Software\\Microsoft\\Windows\\'
'ShellNoRoam\\BagMRU')])
_DEFINITION_FILE = os.path.join(
os.path.dirname(__file__), 'mru.yaml')
def _ParseMRUListExEntryValue(
self, parser_mediator, registry_key, entry_number, parent_path_segments,
codepage='cp1252'):
"""Parses the MRUListEx entry value.
Args:
parser_mediator (ParserMediator): mediates interactions between parsers
and other components, such as storage and dfVFS.
registry_key (dfwinreg.WinRegistryKey): Windows Registry key that contains
the MRUListEx value.
entry_number (int): entry number.
parent_path_segments (list[str]): parent shell item path segments.
codepage (Optional[str]): extended ASCII string codepage.
Returns:
tuple[str, str]: path and upper path segment of the shell item or
None, None if not available.
"""
value = registry_key.GetValueByName(f'{entry_number:d}')
if value is None:
parser_mediator.ProduceExtractionWarning((
f'Missing MRUListEx entry value: {entry_number:d} in key: '
f'{registry_key.path:s}'))
return None, None
if not value.DataIsBinaryData():
parser_mediator.ProduceExtractionWarning((
f'Non-binary MRUListEx entry value: {entry_number:d} in key: '
f'{registry_key.path:s}'))
return None, None
path = None
upper_path_segment = None
if value.data:
shell_items_parser = shell_items.ShellItemsParser(registry_key.path)
shell_items_parser.ParseByteStream(
parser_mediator, value.data,
parent_path_segments=parent_path_segments, codepage=codepage)
path = shell_items_parser.CopyToPath()
upper_path_segment = shell_items_parser.GetUpperPathSegment()
return path, upper_path_segment
def _ParseMRUListExValue(self, registry_key):
"""Parses the MRUListEx value in a given Registry key.
Args:
registry_key (dfwinreg.WinRegistryKey): Windows Registry key that contains
the MRUListEx value.
Returns:
mrulistex_entries: MRUListEx entries or None if not available.
"""
mrulistex_value = registry_key.GetValueByName('MRUListEx')
# The key exists but does not contain a value named "MRUList".
if not mrulistex_value:
return None
mrulistex_entries_map = self._GetDataTypeMap('mrulistex_entries')
context = dtfabric_data_maps.DataTypeMapContext(values={
'data_size': len(mrulistex_value.data)})
return self._ReadStructureFromByteStream(
mrulistex_value.data, 0, mrulistex_entries_map, context=context)
def _ParseSubKey(
self, parser_mediator, registry_key, parent_path_segments,
codepage='cp1252'):
"""Extract event objects from a MRUListEx Registry key.
Args:
parser_mediator (ParserMediator): mediates interactions between parsers
and other components, such as storage and dfVFS.
registry_key (dfwinreg.WinRegistryKey): Windows Registry key.
parent_path_segments (list[str]): parent shell item path segments.
codepage (Optional[str]): extended ASCII string codepage.
"""
try:
mrulistex = self._ParseMRUListExValue(registry_key)
except (ValueError, errors.ParseError) as exception:
parser_mediator.ProduceExtractionWarning(
f'unable to parse MRUListEx value with error: {exception!s}')
return
if not mrulistex:
return
entries = []
entry_numbers = {}
found_terminator = False
for entry_index, entry_number in enumerate(mrulistex):
# The MRU list is terminated with -1 (0xffffffff).
if entry_number == -1:
continue
if found_terminator:
parser_mediator.ProduceExtractionWarning((
f'found additional MRUListEx entries after terminator in key: '
f'{registry_key.path:s}'))
# Only create one parser error per terminator.
found_terminator = False
path, upper_path_segment = self._ParseMRUListExEntryValue(
parser_mediator, registry_key, entry_number, parent_path_segments,
codepage=codepage)
entry_numbers[entry_number] = upper_path_segment
display_entry_index = entry_index + 1
display_path = path or 'N/A'
entries.append((
f'Index: {display_entry_index:d} [MRU Value {entry_number:d}]: '
f'Shell item path: {display_path:s}'))
event_data = BagMRUEventData()
event_data.entries = ' '.join(entries) or None
event_data.key_path = registry_key.path
event_data.last_written_time = registry_key.last_written_time
parser_mediator.ProduceEventData(event_data)
for entry_number, path_segment in entry_numbers.items():
sub_key = registry_key.GetSubkeyByName(f'{entry_number:d}')
if not sub_key:
parser_mediator.ProduceExtractionWarning((
f'Missing BagMRU sub key: {entry_number:d} in key: '
f'{registry_key.path:s}'))
continue
parent_path_segments.append(path_segment)
self._ParseSubKey(
parser_mediator, sub_key, parent_path_segments, codepage=codepage)
parent_path_segments.pop()
# pylint: disable=arguments-differ
winreg_parser.WinRegistryParser.RegisterPlugin(BagMRUWindowsRegistryPlugin)