-
Notifications
You must be signed in to change notification settings - Fork 325
/
winevtx.py
272 lines (218 loc) · 9.42 KB
/
winevtx.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
# -*- coding: utf-8 -*-
"""Parser for Windows XML EventLog (EVTX) files."""
import pyevtx
from dfdatetime import filetime as dfdatetime_filetime
from dfdatetime import semantic_time as dfdatetime_semantic_time
from plaso.containers import events
from plaso.containers import time_events
from plaso.lib import definitions
from plaso.lib import specification
from plaso.parsers import interface
from plaso.parsers import manager
class WinEvtxRecordEventData(events.EventData):
"""Windows XML EventLog (EVTX) record event data.
Attributes:
computer_name (str): computer name stored in the event record.
event_identifier (int): event identifier.
event_level (int): event level.
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.
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.computer_name = None
self.event_identifier = None
self.event_level = 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.xml_string = None
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.source_name = evtx_record.source_name
# Computer name is the value stored in the event record and does not
# necessarily corresponds 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:
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 is None:
date_time = dfdatetime_semantic_time.NotSet()
else:
date_time = dfdatetime_filetime.Filetime(timestamp=written_time)
event = time_events.DateTimeValuesEvent(
date_time, definitions.TIME_DESCRIPTION_WRITTEN)
parser_mediator.ProduceEventWithEventData(event, event_data)
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 = time_events.DateTimeValuesEvent(
date_time, definitions.TIME_DESCRIPTION_CREATION)
parser_mediator.ProduceEventWithEventData(event, 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))
@classmethod
def GetFormatSpecification(cls):
"""Retrieves the format specification.
Returns:
FormatSpecification: format specification.
"""
format_specification = specification.FormatSpecification(cls.NAME)
format_specification.AddNewSignature(b'ElfFile\x00', offset=0)
return format_specification
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.
"""
evtx_file = pyevtx.file()
evtx_file.set_ascii_codepage(parser_mediator.codepage)
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)