# -*- coding: utf-8 -*-
"""Parser for Windows XML EventLog (EVTX) files."""
import pyevtx
from dfdatetime import filetime as dfdatetime_filetime
from plaso.containers import events
from plaso.lib import specification
from plaso.parsers import interface
from plaso.parsers import manager
[docs]class WinEvtxRecordEventData(events.EventData):
"""Windows XML EventLog (EVTX) record event data.
Attributes:
creation_time (dfdatetime.DateTimeValues): event record creation date
and time.
computer_name (str): computer name stored in the event record.
event_identifier (int): event identifier.
event_level (int): event level.
event_version (int): event version.
message_identifier (int): event message identifier.
offset (int): offset of the EVTX record relative to the start of the file,
from which the event data was extracted.
provider_identifier (str): identifier of the EventLog provider.
record_number (int): event record number.
recovered (bool): True if the record was recovered.
source_name (str): name of the event source.
strings (list[str]): event strings.
user_sid (str): user security identifier (SID) stored in the event record.
written_time (dfdatetime.DateTimeValues): event record written date and
time.
xml_string (str): XML representation of the event.
"""
DATA_TYPE = 'windows:evtx:record'
def __init__(self):
"""Initializes event data."""
super(WinEvtxRecordEventData, self).__init__(data_type=self.DATA_TYPE)
self.creation_time = None
self.computer_name = None
self.event_identifier = None
self.event_level = None
self.event_version = None
self.message_identifier = None
self.offset = None
self.provider_identifier = None
self.record_number = None
self.recovered = None
self.source_name = None
self.strings = None
self.user_sid = None
self.written_time = None
self.xml_string = None
[docs]class WinEvtxParser(interface.FileObjectParser):
"""Parses Windows XML EventLog (EVTX) files."""
_INITIAL_FILE_OFFSET = None
NAME = 'winevtx'
DATA_FORMAT = 'Windows XML EventLog (EVTX) file'
def _GetEventDataFromRecord(
self, parser_mediator, record_index, evtx_record, recovered=False):
"""Extract data from a Windows XML EventLog (EVTX) record.
Args:
parser_mediator (ParserMediator): mediates interactions between parsers
and other components, such as storage and dfVFS.
record_index (int): event record index.
evtx_record (pyevtx.record): event record.
recovered (Optional[bool]): True if the record was recovered.
Return:
WinEvtxRecordEventData: event data.
"""
event_data = WinEvtxRecordEventData()
try:
event_data.record_number = evtx_record.identifier
except OverflowError as exception:
warning_message = (
'unable to read record identifier from event record: {0:d} '
'with error: {1!s}').format(record_index, exception)
if recovered:
parser_mediator.ProduceRecoveryWarning(warning_message)
else:
parser_mediator.ProduceExtractionWarning(warning_message)
try:
event_identifier = evtx_record.event_identifier
except OverflowError as exception:
warning_message = (
'unable to read event identifier from event record: {0:d} '
'with error: {1!s}').format(record_index, exception)
if recovered:
parser_mediator.ProduceRecoveryWarning(warning_message)
else:
parser_mediator.ProduceExtractionWarning(warning_message)
event_identifier = None
try:
event_identifier_qualifiers = evtx_record.event_identifier_qualifiers
except OverflowError as exception:
warning_message = (
'unable to read event identifier qualifiers from event record: '
'{0:d} with error: {1!s}').format(record_index, exception)
if recovered:
parser_mediator.ProduceRecoveryWarning(warning_message)
else:
parser_mediator.ProduceExtractionWarning(warning_message)
event_identifier_qualifiers = None
event_data.offset = evtx_record.offset
event_data.recovered = recovered
if event_identifier is not None:
event_data.event_identifier = event_identifier
event_data.message_identifier = event_identifier
if event_identifier_qualifiers is not None:
event_data.message_identifier |= event_identifier_qualifiers << 16
if evtx_record.provider_identifier:
event_data.provider_identifier = evtx_record.provider_identifier.lower()
event_data.event_level = evtx_record.event_level
event_data.event_version = evtx_record.event_version
event_data.source_name = evtx_record.source_name
# Computer name is the value stored in the event record and does not
# necessarily correspond with the actual hostname.
event_data.computer_name = evtx_record.computer_name
event_data.user_sid = evtx_record.user_security_identifier
event_data.strings = list(evtx_record.strings)
event_data.xml_string = evtx_record.xml_string
return event_data
def _ParseRecord(
self, parser_mediator, record_index, evtx_record, recovered=False):
"""Extract data from a Windows XML EventLog (EVTX) record.
Args:
parser_mediator (ParserMediator): mediates interactions between parsers
and other components, such as storage and dfVFS.
record_index (int): event record index.
evtx_record (pyevtx.record): event record.
recovered (Optional[bool]): True if the record was recovered.
"""
event_data = self._GetEventDataFromRecord(
parser_mediator, record_index, evtx_record, recovered=recovered)
try:
creation_time = evtx_record.get_creation_time_as_integer()
except OverflowError as exception:
warning_message = (
'unable to read creation time from event record: {0:d} '
'with error: {1!s}').format(record_index, exception)
if recovered:
parser_mediator.ProduceRecoveryWarning(warning_message)
else:
parser_mediator.ProduceExtractionWarning(warning_message)
creation_time = None
if creation_time:
event_data.creation_time = dfdatetime_filetime.Filetime(
timestamp=creation_time)
try:
written_time = evtx_record.get_written_time_as_integer()
except OverflowError as exception:
warning_message = (
'unable to read written time from event record: {0:d} '
'with error: {1!s}').format(record_index, exception)
if recovered:
parser_mediator.ProduceRecoveryWarning(warning_message)
else:
parser_mediator.ProduceExtractionWarning(warning_message)
written_time = None
if written_time:
event_data.written_time = dfdatetime_filetime.Filetime(
timestamp=written_time)
parser_mediator.ProduceEventData(event_data)
def _ParseRecords(self, parser_mediator, evtx_file):
"""Parses Windows XML EventLog (EVTX) records.
Args:
parser_mediator (ParserMediator): mediates interactions between parsers
and other components, such as storage and dfVFS.
evtx_file (pyevtx.file): Windows XML EventLog (EVTX) file.
"""
# To handle errors when parsing a Windows XML EventLog (EVTX) file in the
# most granular way the following code iterates over every event record.
# The call to evt_file.get_record() and access to members of evt_record
# should be called within a try-except.
for record_index in range(evtx_file.number_of_records):
if parser_mediator.abort:
break
try:
evtx_record = evtx_file.get_record(record_index)
self._ParseRecord(parser_mediator, record_index, evtx_record)
except IOError as exception:
parser_mediator.ProduceExtractionWarning(
'unable to parse event record: {0:d} with error: {1!s}'.format(
record_index, exception))
for record_index in range(evtx_file.number_of_recovered_records):
if parser_mediator.abort:
break
try:
evtx_record = evtx_file.get_recovered_record(record_index)
self._ParseRecord(
parser_mediator, record_index, evtx_record, recovered=True)
except IOError as exception:
parser_mediator.ProduceRecoveryWarning((
'unable to parse recovered event record: {0:d} with error: '
'{1!s}').format(record_index, exception))
[docs] def ParseFileObject(self, parser_mediator, file_object):
"""Parses a Windows XML EventLog (EVTX) file-like object.
Args:
parser_mediator (ParserMediator): mediates interactions between parsers
and other components, such as storage and dfVFS.
file_object (dfvfs.FileIO): a file-like object.
"""
code_page = parser_mediator.GetCodePage()
evtx_file = pyevtx.file()
evtx_file.set_ascii_codepage(code_page)
try:
evtx_file.open_file_object(file_object)
except IOError as exception:
parser_mediator.ProduceExtractionWarning(
'unable to open file with error: {0!s}'.format(exception))
return
try:
self._ParseRecords(parser_mediator, evtx_file)
finally:
evtx_file.close()
manager.ParsersManager.RegisterParser(WinEvtxParser)