/
event_filter.py
191 lines (165 loc) · 9.98 KB
/
event_filter.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
import win32evtlog
import xmltodict
import win32api,win32con
from utils import utc_to_local, notification, check_reg_symlink
service_outlier_executables_history = {}
outlier_parents_of_cmd_history = {}
suspicious_parent = {}
events_by_id = {i: [] for i in range(24)}
# HKCU\Software\Classes\
reg_hijack_dict = {
# "C:\Windows\WinSxS\amd64_microsoft-windows-fodhelper-ux_31bf3856ad364e35_10.0.19041.1_none_e8e077950faced1a\fodhelper.exe"
"fodhelper.exe": r"ms-settings\Shell\Open\command\(Default)",
# "C:\Windows\WinSxS\amd64_microsoft-windows-safedocs-main_31bf3856ad364e35_10.0.19041.610_none_031d733ac584ef8d\sdclt.exe"
"sdclt.exe": r"Folder\Shell\Open\command\(Default)",
# "C:\Windows\WinSxS\amd64_microsoft-windows-s..e-client-ui-wsreset_31bf3856ad364e35_10.0.19041.1_none_7c69077ba55f962b\WSReset.exe"
"WSReset.exe": r"AppX82a6gwre4fdg3bt635tn5ctqjf8msdd2\Shell\Open\command\(Default)",
# "C:\Windows\WinSxS\amd64_microsoft-windows-security-spp-ux_31bf3856ad364e35_10.0.19041.572_none_399674cffdbd6a66\slui.exe"
"slui.exe": r"Launcher.SystemSettings\Shell\Open\command\(Default)"
}
def reg_symhij_check(path_seg):
'''
循环检测一段路径上是否有符号链接，有则返回符号链接的路径，没有则返回None
'''
reg_root = win32con.HKEY_CURRENT_USER
current = 'Software\\Classes'
path_seg = path_seg.split('\\')
for seg in path_seg:
current = '\\'.join([current, seg])
if check_reg_symlink(reg_root, current):
return current
def event_main_filter(event):
'''
判断事件中是否存在可能的UAC绕过行为
'''
record = win32evtlog.EvtRender(event, win32evtlog.EvtRenderEventXml)
record_dict = xmltodict.parse(record)
# 转换为本地时区
evt_local_time = utc_to_local(record_dict['Event']['System']['TimeCreated']['@SystemTime'])
record_dict['Event']['System']['TimeCreated']['@SystemTime'] = evt_local_time
temp_data = {}
for data in record_dict['Event']['EventData']['Data']:
if '#text' in data:
temp_data[data['@Name']] = data['#text']
elif data == None or data == 'None':
temp_data = {}
else:
temp_data[data['@Name']] = None
record_dict['Event']['EventData'] = temp_data
evt_id = int(record_dict['Event']['System']['EventID'])
if evt_id == 1:
image = str(record_dict['Event']['EventData']['Image'])
parent_image = str(record_dict['Event']['EventData']['ParentImage'])
if parent_image == "C:\\Windows\\System32\\services.exe":
service_outlier_executables_history[image] = 0
if 'cmd.exe' in image:
outlier_parents_of_cmd_history[parent_image] = 0
# events_by_id[evt_id].append({'image': record_dict['Event']['EventData']['Image']})
if 'ParentCommandLine' in record_dict['Event']['EventData']:
# COM-ICMLuaUtils-bypassUAC
# 'C:\\WINDOWS\\system32\\DllHost.exe /Processid:{3E5FC7F9-9A51-4367-9063-A120244FBEC7}':
if '{3E5FC7F9-9A51-4367-9063-A120244FBEC7}' in \
record_dict['Event']['EventData']['ParentCommandLine'].upper():
print('COM-ICMLuaUtils-bypassUAC')
print(record_dict['Event']['EventData']['ParentCommandLine'])
notification('COM-ICMLuaUtils-bypassUAC Detected!')
# 判断是不是会被劫持的自动提权exe启动，是则检查对应的会被劫持的路径。
for ex in reg_hijack_dict:
if (image.lower().startswith(r'C:\Windows\WinSxS'.lower()) or image.lower().startswith(r'C:\Windows\System32'.lower())) and ex.lower() in image.lower():
# check reg symlink
sym_path = reg_symhij_check(reg_hijack_dict[ex])
if sym_path != None:
print('Possible registry UAC Hijack with symlink!')
print(f'Path:{sym_path}')
notification('Possible registry UAC Hijack with symlink!', f'Path:{sym_path}')
# if evt_id == 2:
# events_by_id[evt_id].append({'image': record_dict['Event']['EventData']['Image'],
# 'target name': record_dict['Event']['EventData']['TargetFilename']})
# SYSMON EVENT ID 6 : DRIVER LOADED INTO KERNEL [DriverLoad]
if evt_id == 6:
if record_dict['Event']['EventData']['Signature'] != 'Microsoft Windows':
events_by_id[evt_id].append({'ImageLoaded': record_dict['Event']['EventData']['ImageLoaded'],
'Signature': record_dict['Event']['EventData']['Signature']})
# SYSMON EVENT ID 7 : DLL (IMAGE) LOADED BY PROCESS [ImageLoad]
if evt_id == 7:
if record_dict['Event']['EventData']['Signature'] != 'Microsoft Windows':
events_by_id[evt_id].append({'Image': record_dict['Event']['EventData']['Image'],
'ImageLoaded': record_dict['Event']['EventData']['ImageLoaded']})
# dotLocal 被劫持dll的加载
current = events_by_id[evt_id][-1]
if '.exe.local\\' in current['ImageLoaded'].lower():
print("dotLocal DLL hijack detected")
print(events_by_id[evt_id][-1])
notification("dotLocal DLL hijack detected", 'Image: {}\nLib: {}'
.format(current['Image'], current['ImageLoaded']))
# SYSMON EVENT ID 8 : REMOTE THREAD CREATED [CreateRemoteThread]
if evt_id == 8:
# 远程线程注入
events_by_id[evt_id].append({'SourceProcessId': record_dict['Event']['EventData']['SourceProcessId'],
'SourceImage': record_dict['Event']['EventData']['SourceImage'],
'TargetProcessId': record_dict['Event']['EventData']['TargetProcessId'],
'TargetImage': record_dict['Event']['EventData']['TargetImage'],
'StartAddress': record_dict['Event']['EventData']['StartAddress'],
'StartModule': record_dict['Event']['EventData']['StartModule'],
'StartFunction': record_dict['Event']['EventData']['StartFunction']})
print("RemoteThreadCreate detected")
print(events_by_id[evt_id][-1])
notification("RemoteThreadCreate detected", 'Source: {}\nTarget: {}'
.format(events_by_id[evt_id][-1]['SourceImage'], events_by_id[evt_id][-1]['TargetImage']))
# SYSMON EVENT ID 11 : FILE CREATED [FileCreate]
if evt_id == 11:
events_by_id[evt_id].append({'ProcessId': record_dict['Event']['EventData']['ProcessId'],
'Image': record_dict['Event']['EventData']['Image'],
'TargetFilename': record_dict['Event']['EventData']['TargetFilename']})
current = events_by_id[evt_id][-1]
# dotLocal机制的DLL劫持检测 - 判断是否有文件创建在'*.exe.local/'的路径内
if '.exe.local\\' in current['TargetFilename'].lower():
print("dotLocal DLL hijack file create!")
print(events_by_id[evt_id][-1])
notification("dotLocal DLL hijack file create!", 'Image: {}\nFile: {}'
.format(current['Image'], current['TargetFilename']))
# SYSMON EVENT ID 12 & 13 & 14 : REGISTRY MODIFICATION [RegistryEvent]
if evt_id == 13:
events_by_id[evt_id].append({'Image': record_dict['Event']['EventData']['Image'],
'TargetObject': record_dict['Event']['EventData']['TargetObject']
})
current = events_by_id[evt_id][-1]
# 打印出得到的注册表事件 - 调试用
# print("Registry value set")
# print(len(record_dict['Event']['EventData']['Details']))
# print(record_dict['Event']['EventData']['Details'][:5])
# print(type(record_dict['Event']['EventData']['Details']))
# print(current)
if '[Reflection.Assembly]::Load' in record_dict['Event']['EventData']['Details'] and \
"[Microsoft.Win32.Registry]" in record_dict['Event']['EventData']['Details']:
print("Fileless Attack - Living off the land.")
print(current)
notification("Fileless Attack!")
if not record_dict['Event']['EventData']['TargetObject'].startswith('HKLM'):
# possibly HKCU
target_path = record_dict['Event']['EventData']['TargetObject']
target = target_path[target_path.rfind('\\') + 1:].lower()
# 检测windir环境变量改变 - 检测部分通过windir劫持的UAC绕过方法
if target == 'windir':
print("Possible UACBypass: windir hijack!")
print(current)
notification("Possible UACBypass: windir hijack!")
# 检测COR_ENABLE_PROFILING环境变量改变 - 检测部分通过C# profile的UAC绕过方法
elif target.upper() == 'COR_ENABLE_PROFILING' or target.upper() == 'COR_PROFILER':
print("Possible UACBypass: C# profile!")
print(current)
notification("Possible UACBypass: C# profile!")
# print(target_path)
value = record_dict['Event']['EventData']['Details']
# 对每个可能被劫持路径判断一下，看看当前修改的注册表是不是用来劫持的位置
for path in reg_hijack_dict.values():
# print((target_path, path))
if path in target_path:
print('Possible registry UAC Hijack!')
print(f'Path:{target_path}\nValue:{value}')
notification('Possible registry UAC Hijack!', f'Path:{target_path}\nValue:{value}')
# ind = current['TargetObject'].find("\\")
# ind = current['TargetObject'].find("\\", ind + 1) + 1
# notification("Registry value set", 'Source: {}\nTarget: {}'
# .format(get_filename(current['Image']),
# current['TargetObject'][ind:]))