-
Notifications
You must be signed in to change notification settings - Fork 1.1k
/
sensor.py
executable file
·1319 lines (1097 loc) · 62.6 KB
/
sensor.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
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
#!/usr/bin/env python
"""
Copyright (c) 2014-2024 Maltrail developers (https://github.com/stamparm/maltrail/)
See the file 'LICENSE' for copying permission
"""
from __future__ import print_function # Requires: Python >= 2.6
import sys
sys.dont_write_bytecode = True
import cProfile
import inspect
import math
import mmap
import optparse
import os
import platform
import re
import socket
import subprocess
import struct
import threading
import time
import traceback
import warnings
from core.addr import inet_ntoa6
from core.addr import addr_port
from core.attribdict import AttribDict
from core.common import check_connection
from core.common import check_sudo
from core.common import check_whitelisted
from core.common import get_ex_message
from core.common import get_text
from core.common import is_local
from core.common import load_trails
from core.common import patch_parser
from core.compat import xrange
from core.datatype import LRUDict
from core.enums import BLOCK_MARKER
from core.enums import CACHE_TYPE
from core.enums import PROTO
from core.enums import TRAIL
from core.log import create_log_directory
from core.log import flush_condensed_events
from core.log import get_error_log_handle
from core.log import log_error
from core.log import log_event
from core.parallel import worker
from core.parallel import write_block
from core.settings import config
from core.settings import CAPTURE_TIMEOUT
from core.settings import CHECK_CONNECTION_MAX_RETRIES
from core.settings import CONFIG_FILE
from core.settings import CONSONANTS
from core.settings import DLT_OFFSETS
from core.settings import DNS_EXHAUSTION_THRESHOLD
from core.settings import GENERIC_SINKHOLE_REGEX
from core.settings import HOMEPAGE
from core.settings import HOURLY_SECS
from core.settings import HTTP_TIME_FORMAT
from core.settings import IGNORE_DNS_QUERY_SUFFIXES
from core.settings import IPPROTO_LUT
from core.settings import IS_WIN
from core.settings import LOCALHOST_IP
from core.settings import LOCAL_SUBDOMAIN_LOOKUPS
from core.settings import MAX_CACHE_ENTRIES
from core.settings import MMAP_ZFILL_CHUNK_LENGTH
from core.settings import NAME
from core.settings import NO_SUCH_NAME_COUNTERS
from core.settings import NO_SUCH_NAME_PER_HOUR_THRESHOLD
from core.settings import INFECTION_SCANNING_THRESHOLD
from core.settings import PORT_SCANNING_THRESHOLD
from core.settings import POTENTIAL_INFECTION_PORTS
from core.settings import read_config
from core.settings import REGULAR_SENSOR_SLEEP_TIME
from core.settings import SNAP_LEN
from core.settings import SUSPICIOUS_CONTENT_TYPES
from core.settings import SUSPICIOUS_DIRECT_DOWNLOAD_EXTENSIONS
from core.settings import SUSPICIOUS_DIRECT_IP_URL_REGEX
from core.settings import SUSPICIOUS_DOMAIN_CONSONANT_THRESHOLD
from core.settings import SUSPICIOUS_DOMAIN_ENTROPY_THRESHOLD
from core.settings import SUSPICIOUS_DOMAIN_LENGTH_THRESHOLD
from core.settings import SUSPICIOUS_HTTP_PATH_REGEXES
from core.settings import SUSPICIOUS_HTTP_REQUEST_PRE_CONDITION
from core.settings import SUSPICIOUS_HTTP_REQUEST_REGEXES
from core.settings import SUSPICIOUS_HTTP_REQUEST_FORCE_ENCODE_CHARS
from core.settings import SUSPICIOUS_PROXY_PROBE_PRE_CONDITION
from core.settings import SUSPICIOUS_UA_REGEX
from core.settings import VALID_DNS_NAME_REGEX
from core.settings import trails
from core.settings import VERSION
from core.settings import WEB_SCANNING_THRESHOLD
from core.settings import WHITELIST
from core.settings import WHITELIST_DIRECT_DOWNLOAD_KEYWORDS
from core.settings import WHITELIST_LONG_DOMAIN_NAME_KEYWORDS
from core.settings import WHITELIST_HTTP_REQUEST_PATHS
from core.settings import WHITELIST_UA_REGEX
from core.update import update_ipcat
from core.update import update_trails
from thirdparty import six
from thirdparty.six.moves import urllib as _urllib
warnings.filterwarnings(action="ignore", category=DeprecationWarning) # NOTE: https://github.com/helpsystems/pcapy/pull/67/files
_buffer = None
_caps = []
_connect_sec = 0
_connect_src_dst = {}
_connect_src_details = {}
_path_src_dst = {}
_path_src_dst_details = {}
_count = 0
_locks = AttribDict()
_multiprocessing = None
_n = None
_result_cache = LRUDict(MAX_CACHE_ENTRIES)
_local_cache = LRUDict(MAX_CACHE_ENTRIES)
_last_syn = None
_last_logged_syn = None
_last_udp = None
_last_logged_udp = None
_done_count = 0
_done_lock = threading.Lock()
_subdomains = {}
_subdomains_sec = None
_dns_exhausted_domains = set()
class _set(set):
pass
try:
import __builtin__
except ImportError:
# Python 3
import builtins as __builtin__
def print(*args, **kwargs):
ret = __builtin__.print(*args, **kwargs)
sys.stdout.flush()
return ret
try:
import pcapy
except ImportError:
if IS_WIN:
sys.exit("[!] please install 'WinPcap' (e.g. 'http://www.winpcap.org/install/') and Pcapy (e.g. 'https://breakingcode.wordpress.com/?s=pcapy')")
else:
msg = "[!] please install 'pcapy or pcapy-ng' (e.g. 'sudo pip%s install pcapy-ng')" % ('3' if six.PY3 else '2')
sys.exit(msg)
def _check_domain_member(query, domains):
parts = query.lower().split('.')
for i in xrange(0, len(parts)):
domain = '.'.join(parts[i:])
if domain in domains:
return True
return False
def _check_domain_whitelisted(query):
result = _result_cache.get((CACHE_TYPE.DOMAIN_WHITELISTED, query))
if result is None:
result = _check_domain_member(re.split(r"(?i)[^A-Z0-9._-]", query or "")[0], WHITELIST)
_result_cache[(CACHE_TYPE.DOMAIN_WHITELISTED, query)] = result
return result
def _check_domain(query, sec, usec, src_ip, src_port, dst_ip, dst_port, proto, packet=None):
if query:
query = query.lower()
if ':' in query:
query = query.split(':', 1)[0]
if query.replace('.', "").isdigit(): # IP address
return
if _result_cache.get((CACHE_TYPE.DOMAIN, query)) is False:
return
result = False
if re.search(VALID_DNS_NAME_REGEX, query) is not None and not _check_domain_whitelisted(query):
parts = query.split('.')
if query.endswith(".ip-adress.com"): # Reference: https://www.virustotal.com/gui/domain/ip-adress.com/relations
_ = '.'.join(parts[:-2])
trail = "%s(.ip-adress.com)" % _
if _ in trails:
result = True
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, proto, TRAIL.DNS, trail, trails[_][0], trails[_][1]), packet)
if not result:
for i in xrange(0, len(parts)):
domain = '.'.join(parts[i:])
if domain in trails:
if domain == query:
trail = domain
else:
_ = ".%s" % domain
trail = "(%s)%s" % (query[:-len(_)], _)
if not (re.search(r"(?i)\A([rd]?ns|nf|mx|nic)\d*\.", query) and any(_ in trails.get(domain, " ")[0] for _ in ("suspicious", "sinkhole"))): # e.g. ns2.nobel.su
if not ((query == trail or parts[0] == "www") and any(_ in trails.get(domain, " ")[0] for _ in ("dynamic", "free web"))): # e.g. noip.com
result = True
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, proto, TRAIL.DNS, trail, trails[domain][0], trails[domain][1]), packet)
break
if not result and config.USE_HEURISTICS:
if len(parts[0]) > SUSPICIOUS_DOMAIN_LENGTH_THRESHOLD and '-' not in parts[0]:
trail = None
if len(parts) > 2:
trail = "(%s).%s" % ('.'.join(parts[:-2]), '.'.join(parts[-2:]))
elif len(parts) == 2:
trail = "(%s).%s" % (parts[0], parts[1])
else:
trail = query
if trail and not any(_ in trail for _ in WHITELIST_LONG_DOMAIN_NAME_KEYWORDS):
result = True
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, proto, TRAIL.DNS, trail, "long domain (suspicious)", "(heuristic)"), packet)
if not result and trails._regex:
match = re.search(trails._regex, query)
if match:
group, trail = [_ for _ in match.groupdict().items() if _[1] is not None][0]
candidate = trails._regex.split("(?P<")[int(group[1:]) + 1]
candidate = candidate.split('>', 1)[-1].rstrip('|')[:-1]
if candidate in trails:
result = True
trail = match.group(0)
prefix, suffix = query[:match.start()], query[match.end():]
if prefix:
trail = "(%s)%s" % (prefix, trail)
if suffix:
trail = "%s(%s)" % (trail, suffix)
trail = trail.replace(".)", ").")
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, proto, TRAIL.DNS, trail, trails[candidate][0], trails[candidate][1]), packet)
if not result and ".onion." in query:
trail = re.sub(r"(\.onion)(\..*)", r"\1(\2)", query)
_ = trail.split('(')[0]
if _ in trails:
result = True
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, proto, TRAIL.DNS, trail, trails[_][0], trails[_][1]), packet)
if result is False:
_result_cache[(CACHE_TYPE.DOMAIN, query)] = False
def _get_local_prefix():
_sources = set(_.split('~')[0] for _ in _connect_src_dst.keys())
_candidates = [re.sub(r"\d+\.\d+\Z", "", _) for _ in _sources]
_ = sorted(((_candidates.count(_), _) for _ in set(_candidates)), reverse=True)
result = _[0][1] if _ else ""
if result:
_result_cache[(CACHE_TYPE.LOCAL_PREFIX, "")] = result
else:
result = _result_cache.get((CACHE_TYPE.LOCAL_PREFIX, ""))
return result or '_'
def _process_packet(packet, sec, usec, ip_offset):
"""
Processes single (raw) IP layer data
"""
global _connect_sec
global _last_syn
global _last_logged_syn
global _last_udp
global _last_logged_udp
global _subdomains_sec
try:
if config.USE_HEURISTICS:
if _locks.connect_sec:
_locks.connect_sec.acquire()
connect_sec = _connect_sec
_connect_sec = sec
if _locks.connect_sec:
_locks.connect_sec.release()
if sec > connect_sec:
for key in _connect_src_dst:
_src_ip, _dst = key.split('~')
if not _dst.isdigit() and len(_connect_src_dst[key]) > PORT_SCANNING_THRESHOLD:
if not check_whitelisted(_src_ip):
_dst_ip = _dst
for _ in _connect_src_details[key]:
log_event((sec, usec, _src_ip, _[2], _dst_ip, _[3], PROTO.TCP, TRAIL.IP, _src_ip, "potential port scanning", "(heuristic)"), packet)
elif len(_connect_src_dst[key]) > INFECTION_SCANNING_THRESHOLD:
_dst_port = _dst
_dst_ip = [_[-1] for _ in _connect_src_details[key]]
_src_port = [_[-2] for _ in _connect_src_details[key]]
if len(_dst_ip) == len(set(_dst_ip)):
if _src_ip.startswith(_get_local_prefix()):
log_event((sec, usec, _src_ip, _src_port[0], _dst_ip[0], _dst_port, PROTO.TCP, TRAIL.PORT, _dst_port, "potential infection", "(heuristic)"), packet)
_connect_src_dst.clear()
_connect_src_details.clear()
for key in _path_src_dst:
if len(_path_src_dst[key]) > WEB_SCANNING_THRESHOLD:
_src_ip, _dst_ip = key.split('~')
_sec, _usec, _src_port, _dst_port, _path = _path_src_dst_details[key].pop()
log_event((_sec, _usec, _src_ip, _src_port, _dst_ip, _dst_port, PROTO.TCP, TRAIL.PATH, "*", "potential web scanning", "(heuristic)"), packet)
_path_src_dst.clear()
_path_src_dst_details.clear()
ip_data = packet[ip_offset:]
ip_version = ord(ip_data[0:1]) >> 4
localhost_ip = LOCALHOST_IP[ip_version]
if ip_version == 0x04: # IPv4
ip_header = struct.unpack("!BBHHHBBH4s4s", ip_data[:20])
fragment_offset = ip_header[4] & 0x1fff
if fragment_offset != 0:
return
iph_length = (ip_header[0] & 0xf) << 2
protocol = ip_header[6]
src_ip = socket.inet_ntoa(ip_header[8])
dst_ip = socket.inet_ntoa(ip_header[9])
elif ip_version == 0x06: # IPv6
# Reference: http://chrisgrundemann.com/index.php/2012/introducing-ipv6-understanding-ipv6-addresses/
ip_header = struct.unpack("!BBHHBB16s16s", ip_data[:40])
iph_length = 40
protocol = ip_header[4]
src_ip = inet_ntoa6(ip_header[6])
dst_ip = inet_ntoa6(ip_header[7])
else:
return
if protocol == socket.IPPROTO_TCP: # TCP
src_port, dst_port, _, _, doff_reserved, flags = struct.unpack("!HHLLBB", ip_data[iph_length:iph_length + 14])
if flags != 2 and config.plugin_functions:
if dst_ip in trails:
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.IP, dst_ip, trails[dst_ip][0], trails[dst_ip][1]), packet, skip_write=True)
elif src_ip in trails and dst_ip != localhost_ip:
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.IP, src_ip, trails[src_ip][0], trails[src_ip][1]), packet, skip_write=True)
if flags == 2: # SYN set (only)
_ = _last_syn
_last_syn = (sec, src_ip, src_port, dst_ip, dst_port)
if _ == _last_syn: # skip bursts
return
if dst_ip in trails or addr_port(dst_ip, dst_port) in trails:
_ = _last_logged_syn
_last_logged_syn = _last_syn
if _ != _last_logged_syn:
trail = addr_port(dst_ip, dst_port)
if trail not in trails:
trail = dst_ip
if not any(_ in trails[trail][0] for _ in ("attacker",)) and not ("parking site" in trails[trail][0] and dst_port not in (80, 443)):
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.IP if ':' not in trail else TRAIL.IPORT, trail, trails[trail][0], trails[trail][1]), packet)
elif (src_ip in trails or addr_port(src_ip, src_port) in trails) and dst_ip != localhost_ip:
_ = _last_logged_syn
_last_logged_syn = _last_syn
if _ != _last_logged_syn:
trail = addr_port(src_ip, src_port)
if trail not in trails:
trail = src_ip
if not any(_ in trails[trail][0] for _ in ("malware",)):
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.IP if ':' not in trail else TRAIL.IPORT, trail, trails[trail][0], trails[trail][1]), packet)
if config.USE_HEURISTICS:
if dst_ip != localhost_ip:
key = "%s~%s" % (src_ip, dst_ip)
if key not in _connect_src_dst:
_connect_src_dst[key] = set()
_connect_src_details[key] = set()
_connect_src_dst[key].add(dst_port)
_connect_src_details[key].add((sec, usec, src_port, dst_port))
if dst_port in POTENTIAL_INFECTION_PORTS:
key = "%s~%s" % (src_ip, dst_port)
if key not in _connect_src_dst:
_connect_src_dst[key] = set()
_connect_src_details[key] = set()
_connect_src_dst[key].add(dst_ip)
_connect_src_details[key].add((sec, usec, src_port, dst_ip))
else:
tcph_length = doff_reserved >> 4
h_size = iph_length + (tcph_length << 2)
tcp_data = get_text(ip_data[h_size:])
if tcp_data.startswith("HTTP/"):
match = re.search(GENERIC_SINKHOLE_REGEX, tcp_data[:2000])
if match:
trail = match.group(0)
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.HTTP, trail, "sinkhole response (malware)", "(heuristic)"), packet)
else:
index = tcp_data.find("<title>")
if index >= 0:
title = tcp_data[index + len("<title>"):tcp_data.find("</title>", index)]
if re.search(r"domain name has been seized by|Domain Seized|Domain Seizure", title):
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.HTTP, title, "seized domain (suspicious)", "(heuristic)"), packet)
content_type = None
first_index = tcp_data.find("\r\nContent-Type:")
if first_index >= 0:
first_index = first_index + len("\r\nContent-Type:")
last_index = tcp_data.find("\r\n", first_index)
if last_index >= 0:
content_type = tcp_data[first_index:last_index].strip().lower()
if content_type and content_type in SUSPICIOUS_CONTENT_TYPES:
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.HTTP, content_type, "content type (suspicious)", "(heuristic)"), packet)
method, path = None, None
if " HTTP/" in tcp_data:
index = tcp_data.find("\r\n")
if index >= 0:
line = tcp_data[:index]
if line.count(' ') == 2 and " HTTP/" in line:
method, path, _ = line.split(' ')
if method and path:
post_data = None
host = dst_ip
first_index = tcp_data.find("\r\nHost:")
path = path.lower()
if first_index >= 0:
first_index = first_index + len("\r\nHost:")
last_index = tcp_data.find("\r\n", first_index)
if last_index >= 0:
host = tcp_data[first_index:last_index]
host = host.strip().lower()
if host.endswith(":80"):
host = host[:-3]
if host and host[0].isalpha() and dst_ip in trails:
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.IP, "%s (%s)" % (dst_ip, host.split(':')[0]), trails[dst_ip][0], trails[dst_ip][1]), packet)
elif re.search(r"\A\d+\.[0-9.]+\Z", host or "") and re.search(SUSPICIOUS_DIRECT_IP_URL_REGEX, "%s%s" % (host, path)):
if not dst_ip.startswith(_get_local_prefix()):
trail = "(%s)%s" % (host, path)
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.HTTP, trail, "potential iot-malware download (suspicious)", "(heuristic)"), packet)
return
elif config.CHECK_HOST_DOMAINS:
_check_domain(host, sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, packet)
elif config.USE_HEURISTICS and config.CHECK_MISSING_HOST:
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.HTTP, "%s%s" % (host, path), "missing host header (suspicious)", "(heuristic)"), packet)
index = tcp_data.find("\r\n\r\n")
if index >= 0:
post_data = tcp_data[index + 4:]
url = None
if config.USE_HEURISTICS and path.startswith('/'):
_path = path.split('/')[1]
key = "%s~%s" % (src_ip, dst_ip)
if key not in _path_src_dst:
_path_src_dst[key] = set()
_path_src_dst[key].add(_path)
if key not in _path_src_dst_details:
_path_src_dst_details[key] = set()
_path_src_dst_details[key].add((sec, usec, src_port, dst_port, path))
elif config.USE_HEURISTICS and dst_port == 80 and path.startswith("http://") and any(_ in path for _ in SUSPICIOUS_PROXY_PROBE_PRE_CONDITION) and not _check_domain_whitelisted(path.split('/')[2]):
trail = re.sub(r"(http://[^/]+/)(.+)", r"\g<1>(\g<2>)", path)
trail = re.sub(r"(http://)([^/(]+)", lambda match: "%s%s" % (match.group(1), match.group(2).split(':')[0].rstrip('.')), trail)
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.HTTP, trail, "potential proxy probe (suspicious)", "(heuristic)"), packet)
return
elif "://" in path:
unquoted_path = _urllib.parse.unquote(path)
key = "code execution"
if key not in _local_cache:
_local_cache[key] = next(_[1] for _ in SUSPICIOUS_HTTP_REQUEST_REGEXES if "code execution" in _[0])
if re.search(_local_cache[key], unquoted_path, re.I) is None: # NOTE: to prevent malware domain FPs in case of outside scanners
url = path.split("://", 1)[1]
if '/' not in url:
url = "%s/" % url
host, path = url.split('/', 1)
if host.endswith(":80"):
host = host[:-3]
path = "/%s" % path
proxy_domain = host.split(':')[0]
_check_domain(proxy_domain, sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, packet)
elif method == "CONNECT":
if '/' in path:
host, path = path.split('/', 1)
path = "/%s" % path
else:
host, path = path, '/'
if host.endswith(":80"):
host = host[:-3]
url = "%s%s" % (host, path)
proxy_domain = host.split(':')[0]
_check_domain(proxy_domain, sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, packet)
if url is None:
url = "%s%s" % (host, path)
if config.USE_HEURISTICS:
user_agent, result = None, None
first_index = tcp_data.find("\r\nUser-Agent:")
if first_index >= 0:
first_index = first_index + len("\r\nUser-Agent:")
last_index = tcp_data.find("\r\n", first_index)
if last_index >= 0:
user_agent = tcp_data[first_index:last_index]
user_agent = _urllib.parse.unquote(user_agent).strip()
if user_agent:
result = _result_cache.get((CACHE_TYPE.USER_AGENT, user_agent))
if result is None:
if re.search(WHITELIST_UA_REGEX, user_agent, re.I) is None:
match = re.search(SUSPICIOUS_UA_REGEX, user_agent)
if match and match.group(0):
def _(value):
return value.rstrip('\\').replace('(', "\\(").replace(')', "\\)")
parts = user_agent.split(match.group(0), 1)
if len(parts) > 1 and parts[0] and parts[-1]:
result = _result_cache[(CACHE_TYPE.USER_AGENT, user_agent)] = "%s (%s)" % (_(match.group(0)), _(user_agent))
else:
result = _result_cache[(CACHE_TYPE.USER_AGENT, user_agent)] = _(match.group(0)).join(("(%s)" if part else "%s") % _(part) for part in parts)
if not result:
_result_cache[(CACHE_TYPE.USER_AGENT, user_agent)] = False
if result:
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.UA, result, "user agent (suspicious)", "(heuristic)"), packet)
if not _check_domain_whitelisted(host):
path = path.replace("//", '/')
unquoted_path = _urllib.parse.unquote(path)
unquoted_post_data = _urllib.parse.unquote(post_data or "")
checks = [path.rstrip('/')]
if '?' in path:
checks.append(path.split('?')[0].rstrip('/'))
if '=' in path:
checks.append(path[:path.index('=') + 1])
_ = re.sub(r"(\w+=)[^&=]+", r"\g<1>", path)
if _ not in checks:
checks.append(_)
if _.count('/') > 1:
checks.append("/%s" % _.split('/')[-1])
elif post_data:
checks.append("%s?%s" % (path, unquoted_post_data.lower()))
if checks[-1].count('/') > 1:
checks.append(checks[-1][:checks[-1].rfind('/')])
checks.append(checks[0][checks[0].rfind('/'):].split('?')[0])
for check in filter(None, checks):
for _ in ("", host):
check = "%s%s" % (_, check)
if check in trails:
if '?' not in path and '?' in check and post_data:
trail = "%s(%s \\(%s %s\\))" % (host, path, method, post_data.strip())
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.HTTP, trail, trails[check][0], trails[check][1]))
else:
parts = url.split(check)
other = ("(%s)" % _ if _ else _ for _ in parts)
trail = check.join(other)
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.URL, trail, trails[check][0], trails[check][1]))
return
if "%s/" % host in trails:
trail = "%s/" % host
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.URL, trail, trails[trail][0], trails[trail][1]))
return
if config.USE_HEURISTICS:
match = re.search(r"\b(CF-Connecting-IP|True-Client-IP|X-Forwarded-For):\s*([0-9.]+)".encode(), packet, re.I)
if match:
src_ip = "%s,%s" % (src_ip, match.group(1))
for char in SUSPICIOUS_HTTP_REQUEST_FORCE_ENCODE_CHARS:
replacement = SUSPICIOUS_HTTP_REQUEST_FORCE_ENCODE_CHARS[char]
path = path.replace(char, replacement)
if post_data:
post_data = post_data.replace(char, replacement)
if not any(_ in unquoted_path.lower() for _ in WHITELIST_HTTP_REQUEST_PATHS):
if any(_ in unquoted_path for _ in SUSPICIOUS_HTTP_REQUEST_PRE_CONDITION):
found = _result_cache.get((CACHE_TYPE.PATH, unquoted_path))
if found is None:
for desc, regex in SUSPICIOUS_HTTP_REQUEST_REGEXES:
if re.search(regex, unquoted_path, re.I | re.DOTALL):
found = desc
break
_result_cache[(CACHE_TYPE.PATH, unquoted_path)] = found or ""
if found and not ("data leakage" in found and is_local(dst_ip)):
trail = "%s(%s)" % (host, path)
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.URL, trail, "%s (suspicious)" % found, "(heuristic)"), packet)
return
if any(_ in unquoted_post_data for _ in SUSPICIOUS_HTTP_REQUEST_PRE_CONDITION):
found = _result_cache.get((CACHE_TYPE.POST_DATA, unquoted_post_data))
if found is None:
for desc, regex in SUSPICIOUS_HTTP_REQUEST_REGEXES:
if re.search(regex, unquoted_post_data, re.I | re.DOTALL):
found = desc
break
_result_cache[(CACHE_TYPE.POST_DATA, unquoted_post_data)] = found or ""
if found:
trail = "%s(%s \\(%s %s\\))" % (host, path, method, post_data.strip())
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.HTTP, trail, "%s (suspicious)" % found, "(heuristic)"), packet)
return
if '.' in path:
_ = _urllib.parse.urlparse("http://%s" % url) # dummy scheme
path = path.lower()
filename = _.path.split('/')[-1]
name, extension = os.path.splitext(filename)
trail = "%s(%s)" % (host, path)
if extension in SUSPICIOUS_DIRECT_DOWNLOAD_EXTENSIONS and not is_local(dst_ip) and not any(_ in path for _ in WHITELIST_DIRECT_DOWNLOAD_KEYWORDS) and '=' not in _.query and len(name) < 10:
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.URL, trail, "direct %s download (suspicious)" % extension, "(heuristic)"), packet)
else:
for desc, regex in SUSPICIOUS_HTTP_PATH_REGEXES:
if re.search(regex, filename, re.I):
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.TCP, TRAIL.URL, trail, "%s (suspicious)" % desc, "(heuristic)"), packet)
break
elif protocol == socket.IPPROTO_UDP: # UDP
_ = ip_data[iph_length:iph_length + 4]
if len(_) < 4:
return
src_port, dst_port = struct.unpack("!HH", _)
_ = _last_udp
_last_udp = (sec, src_ip, src_port, dst_ip, dst_port)
if _ == _last_udp: # skip bursts
return
if src_port != 53 and dst_port != 53: # not DNS
if dst_ip in trails:
trail = dst_ip
elif src_ip in trails:
trail = src_ip
else:
trail = None
if trail:
_ = _last_logged_udp
_last_logged_udp = _last_udp
if _ != _last_logged_udp:
if not any(_ in trails[trail][0] for _ in ("malware",)):
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.UDP, TRAIL.IP, trail, trails[trail][0], trails[trail][1]), packet)
else:
dns_data = ip_data[iph_length + 8:]
# Reference: http://www.ccs.neu.edu/home/amislove/teaching/cs4700/fall09/handouts/project1-primer.pdf
if len(dns_data) > 6:
qdcount = struct.unpack("!H", dns_data[4:6])[0]
if qdcount > 0:
offset = 12
query = ""
while len(dns_data) > offset:
length = ord(dns_data[offset:offset + 1])
if not length:
query = query[:-1]
break
query += get_text(dns_data[offset + 1:offset + length + 1]) + '.'
offset += length + 1
query = query.lower()
if not query or re.search(VALID_DNS_NAME_REGEX, query) is None or any(_ in query for _ in (".intranet.",)) or query.split('.')[-1] in IGNORE_DNS_QUERY_SUFFIXES:
return
parts = query.split('.')
if ord(dns_data[2:3]) & 0xfa == 0x00: # standard query (both recursive and non-recursive)
type_, class_ = struct.unpack("!HH", dns_data[offset + 1:offset + 5])
if len(parts) > 2:
if len(parts) > 3 and len(parts[-2]) <= 3:
domain = '.'.join(parts[-3:])
else:
domain = '.'.join(parts[-2:])
if not _check_domain_whitelisted(domain): # e.g. <hash>.hashserver.cs.trendmicro.com
if (sec - (_subdomains_sec or 0)) > HOURLY_SECS:
_subdomains.clear()
_dns_exhausted_domains.clear()
_subdomains_sec = sec
subdomains = _subdomains.get(domain)
if not subdomains:
subdomains = _subdomains[domain] = _set()
subdomains._start = sec
if not re.search(r"\A\d+\-\d+\-\d+\-\d+\Z", parts[0]):
if sec - subdomains._start > 60:
subdomains._start = sec
subdomains.clear()
elif len(subdomains) < DNS_EXHAUSTION_THRESHOLD:
subdomains.add('.'.join(parts[:-2]))
else:
trail = "(%s).%s" % ('.'.join(parts[:-2]), '.'.join(parts[-2:]))
if re.search(r"bl\b", trail) is None: # generic check for DNSBLs
if not any(_ in subdomains for _ in LOCAL_SUBDOMAIN_LOOKUPS): # generic check for local DNS resolutions
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.UDP, TRAIL.DNS, trail, "potential dns exhaustion (suspicious)", "(heuristic)"), packet)
_dns_exhausted_domains.add(domain)
return
# Reference: http://en.wikipedia.org/wiki/List_of_DNS_record_types
if type_ not in (12, 28) and class_ == 1: # Type not in (PTR, AAAA), Class IN
if addr_port(dst_ip, dst_port) in trails:
trail = addr_port(dst_ip, dst_port)
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.UDP, TRAIL.IPORT, "%s (%s)" % (dst_ip, query), trails[trail][0], trails[trail][1]), packet)
elif dst_ip in trails:
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.UDP, TRAIL.IP, "%s (%s)" % (dst_ip, query), trails[dst_ip][0], trails[dst_ip][1]), packet)
elif src_ip in trails:
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.UDP, TRAIL.IP, src_ip, trails[src_ip][0], trails[src_ip][1]), packet)
_check_domain(query, sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.UDP, packet)
elif config.USE_HEURISTICS:
if ord(dns_data[2:3]) & 0x80: # standard response
if ord(dns_data[3:4]) == 0x80: # recursion available, no error
_ = offset + 5
try:
while _ < len(dns_data):
if ord(dns_data[_:_ + 1]) & 0xc0 != 0 and dns_data[_ + 2] == "\00" and dns_data[_ + 3] == "\x01": # Type A
break
else:
_ += 12 + struct.unpack("!H", dns_data[_ + 10: _ + 12])[0]
_ = dns_data[_ + 12:_ + 16]
if _:
answer = socket.inet_ntoa(_)
if answer in trails and not _check_domain_whitelisted(query):
_ = trails[answer]
if "sinkhole" in _[0]:
trail = "(%s).%s" % ('.'.join(parts[:-1]), '.'.join(parts[-1:]))
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.UDP, TRAIL.DNS, trail, "sinkholed by %s (malware)" % _[0].split(" ")[1], "(heuristic)"), packet) # (e.g. kitro.pl, devomchart.com, jebena.ananikolic.su, vuvet.cn)
elif "parking" in _[0]:
trail = "(%s).%s" % ('.'.join(parts[:-1]), '.'.join(parts[-1:]))
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.UDP, TRAIL.DNS, trail, "parked site (suspicious)", "(heuristic)"), packet)
except IndexError:
pass
elif ord(dns_data[3:4]) == 0x83: # recursion available, no such name
if '.'.join(parts[-2:]) not in _dns_exhausted_domains and not _check_domain_whitelisted(query) and not _check_domain_member(query, trails):
if parts[-1].isdigit():
return
if not (len(parts) > 4 and all(_.isdigit() and int(_) < 256 for _ in parts[:4])): # generic check for DNSBL IP lookups
if not is_local(dst_ip): # prevent FPs caused by local queries
for _ in filter(None, (query, "*.%s" % '.'.join(parts[-2:]) if query.count('.') > 1 else None)):
if _ not in NO_SUCH_NAME_COUNTERS or NO_SUCH_NAME_COUNTERS[_][0] != sec // 3600:
NO_SUCH_NAME_COUNTERS[_] = [sec // 3600, 1, set()]
else:
NO_SUCH_NAME_COUNTERS[_][1] += 1
NO_SUCH_NAME_COUNTERS[_][2].add(query)
if NO_SUCH_NAME_COUNTERS[_][1] > NO_SUCH_NAME_PER_HOUR_THRESHOLD:
if _.startswith("*."):
trail = "%s%s" % ("(%s)" % ','.join(item.replace(_[1:], "") for item in NO_SUCH_NAME_COUNTERS[_][2]), _[1:])
if not any(subdomain in trail for subdomain in LOCAL_SUBDOMAIN_LOOKUPS): # generic check for local DNS resolutions
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.UDP, TRAIL.DNS, trail, "excessive no such domain (suspicious)", "(heuristic)"), packet)
for item in NO_SUCH_NAME_COUNTERS[_][2]:
try:
del NO_SUCH_NAME_COUNTERS[item]
except KeyError:
pass
else:
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.UDP, TRAIL.DNS, _, "excessive no such domain (suspicious)", "(heuristic)"), packet)
try:
del NO_SUCH_NAME_COUNTERS[_]
except KeyError:
pass
break
if len(parts) == 2 and parts[0] and '-' not in parts[0]:
part = parts[0]
trail = "(%s).%s" % (parts[0], parts[1])
result = _result_cache.get(part)
if result is None:
# Reference: https://github.com/exp0se/dga_detector
probabilities = (float(part.count(c)) / len(part) for c in set(_ for _ in part))
entropy = -sum(p * math.log(p) / math.log(2.0) for p in probabilities)
if entropy > SUSPICIOUS_DOMAIN_ENTROPY_THRESHOLD:
result = "entropy threshold no such domain (suspicious)"
if not result:
if sum(_ in CONSONANTS for _ in part) > SUSPICIOUS_DOMAIN_CONSONANT_THRESHOLD:
result = "consonant threshold no such domain (suspicious)"
_result_cache[part] = result or False
if result:
log_event((sec, usec, src_ip, src_port, dst_ip, dst_port, PROTO.UDP, TRAIL.DNS, trail, result, "(heuristic)"), packet)
elif protocol in IPPROTO_LUT: # non-TCP/UDP (e.g. ICMP)
if protocol == socket.IPPROTO_ICMP:
if ord(ip_data[iph_length:iph_length + 1]) != 0x08: # Non-echo request
return
elif protocol == socket.IPPROTO_ICMPV6:
if ord(ip_data[iph_length:iph_length + 1]) != 0x80: # Non-echo request
return
if dst_ip in trails:
log_event((sec, usec, src_ip, '-', dst_ip, '-', IPPROTO_LUT[protocol], TRAIL.IP, dst_ip, trails[dst_ip][0], trails[dst_ip][1]), packet)
elif src_ip in trails:
log_event((sec, usec, src_ip, '-', dst_ip, '-', IPPROTO_LUT[protocol], TRAIL.IP, src_ip, trails[src_ip][0], trails[src_ip][1]), packet)
except struct.error:
pass
except Exception:
if config.SHOW_DEBUG:
traceback.print_exc()
def init():
"""
Performs sensor initialization
"""
global _multiprocessing
try:
import multiprocessing
if config.PROCESS_COUNT > 1 and not config.profile:
_multiprocessing = multiprocessing
except (ImportError, OSError, NotImplementedError):
pass
def update_timer():
retries = 0
if not config.offline:
while retries < CHECK_CONNECTION_MAX_RETRIES and not check_connection():
sys.stdout.write("[!] can't update because of lack of Internet connection (waiting..." if not retries else '.')
sys.stdout.flush()
time.sleep(10)
retries += 1
if retries:
print(")")
if config.offline or retries == CHECK_CONNECTION_MAX_RETRIES:
if retries == CHECK_CONNECTION_MAX_RETRIES:
print("[x] going to continue without online update")
_ = update_trails(offline=True)
else:
_ = update_trails()
update_ipcat()
if _:
trails.clear()
trails.update(_)
elif not trails:
_ = load_trails()
trails.update(_)
_regex = ""
for trail in trails:
if "static" in trails[trail][1]:
if re.search(r"[\].][*+]|\[[a-z0-9_.\-]+\]", trail, re.I):
try:
re.compile(trail)
except re.error:
pass
else:
if re.escape(trail) != trail:
index = _regex.count("(?P<g")
if index < 100: # Reference: https://stackoverflow.com/questions/478458/python-regular-expressions-with-more-than-100-groups
_regex += "|(?P<g%s>%s)" % (index, trail)
trails._regex = _regex.strip('|')
thread = threading.Timer(config.UPDATE_PERIOD, update_timer)
thread.daemon = True
thread.start()
create_log_directory()
get_error_log_handle()
msg = "[i] using '%s' for trail storage" % config.TRAILS_FILE
if os.path.isfile(config.TRAILS_FILE):
mtime = time.gmtime(os.path.getmtime(config.TRAILS_FILE))
msg += " (last modification: '%s')" % time.strftime(HTTP_TIME_FORMAT, mtime)
print(msg)
update_timer()
if not config.DISABLE_CHECK_SUDO and check_sudo() is False:
sys.exit("[!] please run '%s' with root privileges" % __file__)
if config.plugins:
config.plugin_functions = []
for plugin in re.split(r"[,;]", config.plugins):
plugin = plugin.strip()
found = False
for _ in (plugin, os.path.join("plugins", plugin), os.path.join("plugins", "%s.py" % plugin)):
if os.path.isfile(_):
plugin = _
found = True
break
if not found:
sys.exit("[!] plugin script '%s' not found" % plugin)
else:
dirname, filename = os.path.split(plugin)
dirname = os.path.abspath(dirname)
if not os.path.exists(os.path.join(dirname, '__init__.py')):
sys.exit("[!] empty file '__init__.py' required inside directory '%s'" % dirname)
if not filename.endswith(".py"):
sys.exit("[!] plugin script '%s' should have an extension '.py'" % filename)
if dirname not in sys.path:
sys.path.insert(0, dirname)
try:
module = __import__(filename[:-3])
except (ImportError, SyntaxError) as msg:
sys.exit("[!] unable to import plugin script '%s' (%s)" % (filename, msg))
found = False
for name, function in inspect.getmembers(module, inspect.isfunction):
if name == "plugin" and not set(inspect.getargspec(function).args) & set(("event_tuple', 'packet")):
found = True
config.plugin_functions.append(function)
function.__name__ = module.__name__
if not found:
sys.exit("[!] missing function 'plugin(event_tuple, packet)' in plugin script '%s'" % filename)
if config.pcap_file:
for _ in config.pcap_file.split(','):
_caps.append(pcapy.open_offline(_))
else:
interfaces = set(_.strip() for _ in config.MONITOR_INTERFACE.split(','))
try:
devices = pcapy.findalldevs()
except:
devices = []
if (config.MONITOR_INTERFACE or "").lower() == "any":
if devices and (IS_WIN or "any" not in devices):
print("[x] virtual interface 'any' missing. Replacing it with all interface names")
interfaces = devices
else:
print("[?] in case of any problems with packet capture on virtual interface 'any', please put all monitoring interfaces to promiscuous mode manually (e.g. 'sudo ifconfig eth0 promisc')")
for interface in interfaces:
if interface.lower() != "any" and devices and re.sub(r"(?i)\Anetmap:", "", interface) not in devices:
hint = "[?] available interfaces: '%s'" % ",".join(devices)
sys.exit("[!] interface '%s' not found\n%s" % (interface, hint))
print("[i] opening interface '%s'" % interface)
try:
_caps.append(pcapy.open_live(interface, SNAP_LEN, True, CAPTURE_TIMEOUT))
except (socket.error, pcapy.PcapError):
if "permitted" in str(sys.exc_info()[1]):
sys.exit("[!] permission problem occurred ('%s')" % sys.exc_info()[1])
elif "No such device" in str(sys.exc_info()[1]):
sys.exit("[!] no such device '%s'" % interface)
else:
raise