forked from spender-sandbox/cuckoomon-modified
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathhooking_64.c
1129 lines (999 loc) · 31.5 KB
/
hooking_64.c
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
#ifdef _WIN64
/*
Cuckoo Sandbox - Automated Malware Analysis
Copyright (C) 2014 Optiv, Inc. ([email protected]), Cuckoo Sandbox Developers
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stddef.h>
#include "ntapi.h"
#include <distorm.h>
#include "hooking.h"
#include "ignore.h"
#include "unhook.h"
#include "misc.h"
#include "pipe.h"
#include "config.h"
extern DWORD g_tls_hook_index;
// do not change this number
#define TLS_LAST_ERROR 0x34
// length disassembler engine
static int lde(void *addr)
{
// the length of an instruction is 16 bytes max, but there can also be
// 16 instructions of length one, so.. we support "decomposing" 16
// instructions at once, max
unsigned int used_instruction_count; _DInst instructions[16];
_CodeInfo code_info = { 0, 0, addr, 16, Decode64Bits };
_DecodeResult ret = distorm_decompose(&code_info, instructions, 16,
&used_instruction_count);
return ret == DECRES_SUCCESS ? instructions[0].size : 0;
}
static _DInst *get_insn(void *addr)
{
unsigned int used_instruction_count; _DInst instructions[16];
_CodeInfo code_info = { 0, 0, addr, 16, Decode64Bits };
_DecodeResult ret = distorm_decompose(&code_info, instructions, 16,
&used_instruction_count);
if (ret == DECRES_SUCCESS) {
_DInst *insn = malloc(sizeof(_DInst));
memcpy(insn, &instructions[0], sizeof(_DInst));
return insn;
}
return NULL;
}
static void put_insn(_DInst *insn)
{
free(insn);
}
static unsigned char *emit_indirect_jmp(unsigned char *buf, ULONG_PTR addr)
{
*buf++ = 0xff;
*buf++ = 0x25;
*(DWORD *)buf = 0;
buf += sizeof(DWORD);
*(ULONG_PTR *)buf = addr;
buf += sizeof(ULONG_PTR);
return buf;
}
static unsigned char *emit_indirect_call(unsigned char *buf, ULONG_PTR addr)
{
*buf++ = 0xff;
*buf++ = 0x15;
*(DWORD *)buf = 2;
buf += sizeof(DWORD);
*buf++ = 0xeb;
*buf++ = 0x08;
*(ULONG_PTR *)buf = addr;
buf += sizeof(ULONG_PTR);
return buf;
}
static unsigned char *emit_indirect_jcc(unsigned char condcode, unsigned char *buf, ULONG_PTR addr)
{
*buf++ = condcode;
*buf++ = 2 + 4 + 8;
*buf++ = 0xff;
*buf++ = 0x25;
*(DWORD *)buf = 0;
buf += sizeof(DWORD);
*(ULONG_PTR *)buf = (ULONG_PTR)buf + 2 + 4 + 8 + 8;
buf += sizeof(ULONG_PTR);
*buf++ = 0xff;
*buf++ = 0x25;
*(DWORD *)buf = 0;
buf += sizeof(DWORD);
*(ULONG_PTR *)buf = addr;
buf += sizeof(ULONG_PTR);
return buf;
}
static ULONG_PTR get_near_rel_target(unsigned char *buf)
{
if (buf[0] == 0xe9 || buf[0] == 0xe8)
return (ULONG_PTR)buf + 5 + *(int *)&buf[1];
else if (buf[0] == 0x0f && buf[1] >= 0x80 && buf[1] < 0x90)
return (ULONG_PTR)buf + 6 + *(int *)&buf[2];
assert(0);
return 0;
}
static ULONG_PTR get_short_rel_target(unsigned char *buf)
{
if (buf[0] == 0xeb || buf[0] == 0xe3 || (buf[0] >= 0x70 && buf[0] < 0x80))
return (ULONG_PTR)buf + 2 + *(char *)&buf[1];
assert(0);
return 0;
}
static ULONG_PTR get_indirect_target(unsigned char *buf)
{
return *(ULONG_PTR *)(buf + 6 + *(int *)&buf[2]);
}
static ULONG_PTR get_corresponding_tramp_target(addr_map_t *map, ULONG_PTR addr)
{
unsigned int i = 0;
while (map->map[i][1]) {
if (map->map[i][1] == addr)
return map->map[i][0];
}
return 0;
}
static int addr_is_in_range(ULONG_PTR addr, const unsigned char *buf, DWORD size)
{
ULONG_PTR start = (ULONG_PTR)buf;
ULONG_PTR end = start + size;
if (addr >= start && addr < end)
return 1;
return 0;
}
static void retarget_rip_relative_displacement(unsigned char **tramp, unsigned char **addr, _DInst *insn)
{
unsigned short length = insn->size;
unsigned char offset = (unsigned char)(length - insn->imm_encoded_size - sizeof(int));
unsigned char *newtramp = *tramp;
unsigned char *newaddr = *addr;
ULONG_PTR target;
int rel = *(int *)(newaddr + offset);
target = (ULONG_PTR)(newaddr + length + rel);
// copy the instruction directly to the trampoline
while (length-- != 0) {
*newtramp++ = *newaddr++;
}
// now replace the displacement
rel = (int)(target - (ULONG_PTR)newtramp);
*(int *)(newtramp - insn->imm_encoded_size - sizeof(int)) = rel;
*tramp = newtramp;
*addr = newaddr;
}
// create a trampoline at the given address, that is, we are going to replace
// the original instructions at this particular address. So, in order to
// call the original function from our hook, we have to execute the original
// instructions *before* jumping into addr+offset, where offset is the length
// which totals the size of the instructions which we place in the `tramp'.
// returns 0 on failure, or a positive integer defining the size of the tramp
// NOTE: tramp represents the memory address where the trampoline will be
// placed, copying it to another memory address will result into failure
static int hook_create_trampoline(unsigned char *addr, int len,
unsigned char *tramp)
{
addr_map_t addrmap;
ULONG_PTR target;
const unsigned char *base = tramp;
const unsigned char *origaddr = addr;
unsigned char insnidx = 0;
int stoleninstrlen = 0;
_DInst *insn;
memset(&addrmap, 0, sizeof(addrmap));
// our trampoline should contain at least enough bytes to fit the given
// length
while (len > 0) {
int length;
insn = get_insn(addr);
if (insn == NULL)
goto error;
length = insn->size;
// how many bytes left?
len -= length;
stoleninstrlen += length;
addrmap.map[insnidx][0] = (ULONG_PTR)tramp;
addrmap.map[insnidx][1] = (ULONG_PTR)addr;
// check the type of instruction at this particular address, if it's
// a jump or a call instruction, then we have to calculate some fancy
// addresses, otherwise we can simply copy the instruction to our
// trampoline
if (addr[0] == 0xe8 || addr[0] == 0xe9 || (addr[0] == 0x0f && addr[1] >= 0x80 && addr[1] < 0x90) ||
(insn->flags & FLAG_RIP_RELATIVE)) {
retarget_rip_relative_displacement(&tramp, &addr, insn);
if (addr[0] == 0xe9 && len > 0)
goto error;
}
else if (addr[0] == 0xeb) {
target = get_short_rel_target(addr);
if (addr_is_in_range(target, origaddr, stoleninstrlen))
target = get_corresponding_tramp_target(&addrmap, target);
tramp = emit_indirect_jmp(tramp, target);
addr += length;
if (len > 0)
goto error;
}
else if (addr[0] == 0xe3 || ((addr[0] & 0xf0) == 0x70)) {
target = get_short_rel_target(addr);
if (addr_is_in_range(target, origaddr, stoleninstrlen))
target = get_corresponding_tramp_target(&addrmap, target);
tramp = emit_indirect_jcc(addr[0], tramp, target);
addr += length;
}
// return instruction, indicates end of basic block as well, so we
// have to check if we already have enough space for our hook..
else if ((addr[0] == 0xc3 || addr[0] == 0xc2) && len > 0) {
goto error;
}
else {
// copy the instruction directly to the trampoline
while (length-- != 0) {
*tramp++ = *addr++;
}
}
put_insn(insn);
}
// append a jump from the trampoline to the original function
*tramp++ = 0xe9;
emit_rel(tramp, tramp, addr);
tramp += 4;
// return the length of this trampoline
return (int)(tramp - base);
error:
if (insn)
put_insn(insn);
return 0;
}
// needs to be updated whenever the assembly below changes
void add_unwind_info(hook_t *h)
{
RUNTIME_FUNCTION *functable;
UNWIND_INFO *unwindinfo;
BYTE regs1[] = { 11, 10, 9, 8 };
BYTE regs2[] = { 3, 2, 1, 0 };
int i, x;
/* would be really nice if MSDN had any mention whatsoever that the RUNTIME_FUNCTION needs to have
a global allocation -- it doesn't copy the contents of the tiny 12-byte RUNTIME_FUNCTION, it merely
stores the same pointer you provide to the API. If you allocate it on the stack, or call the API multiple
times with the same pointer value, you'll end up with completely broken unwind information that fails
in spectacular ways.
*/
functable = malloc(sizeof(RUNTIME_FUNCTION));
unwindinfo = &h->hookdata->unwind_info;
functable->BeginAddress = offsetof(hook_data_t, pre_tramp);
functable->EndAddress = offsetof(hook_data_t, pre_tramp) + sizeof(h->hookdata->pre_tramp);
functable->UnwindData = offsetof(hook_data_t, unwind_info);
unwindinfo->Version = 1;
unwindinfo->Flags = UNW_FLAG_NHANDLER;
if (h->notail && h->numargs > 4) {
unwindinfo->SizeOfProlog = 0xad;
}
else if (h->notail) {
unwindinfo->SizeOfProlog = 0x7d;
}
else {
unwindinfo->SizeOfProlog = 50;
}
unwindinfo->FrameRegister = 0;
unwindinfo->FrameOffset = 0;
i = 0;
if (h->notail && h->numargs > 4) {
unwindinfo->UnwindCode[i].UnwindOp = UWOP_ALLOC_SMALL;
unwindinfo->UnwindCode[i].CodeOffset = 0xa7;
unwindinfo->UnwindCode[i].OpInfo = 3; // (3 + 1) * 8 = 0x20
i++;
unwindinfo->UnwindCode[i].UnwindOp = UWOP_ALLOC_SMALL;
unwindinfo->UnwindCode[i].CodeOffset = 0x9a;
unwindinfo->UnwindCode[i].OpInfo = h->numargs - 5;
i++;
if (h->numargs & 1) {
unwindinfo->UnwindCode[i].UnwindOp = UWOP_ALLOC_SMALL;
unwindinfo->UnwindCode[i].CodeOffset = 0x97;
unwindinfo->UnwindCode[i].OpInfo = 0; // (0 + 1) * 8 = 8
i++;
}
}
if (h->notail) {
unwindinfo->UnwindCode[i].UnwindOp = UWOP_ALLOC_SMALL;
unwindinfo->UnwindCode[i].CodeOffset = 0x2e;
unwindinfo->UnwindCode[i].OpInfo = 3; // (3 + 1) * 8 = 0x20
i++;
for (x = 0; x < ARRAYSIZE(regs1); x++) {
unwindinfo->UnwindCode[x + i].UnwindOp = UWOP_PUSH_NONVOL;
unwindinfo->UnwindCode[x + i].CodeOffset = 16 - (2 * x);
unwindinfo->UnwindCode[x + i].OpInfo = regs1[x];
}
i += x;
for (x = 0; x < ARRAYSIZE(regs2); x++) {
unwindinfo->UnwindCode[x + i].UnwindOp = UWOP_PUSH_NONVOL;
unwindinfo->UnwindCode[x + i].CodeOffset = 8 - x;
unwindinfo->UnwindCode[x + i].OpInfo = regs2[x];
}
i += x;
// rdi
unwindinfo->UnwindCode[i].UnwindOp = UWOP_PUSH_NONVOL;
unwindinfo->UnwindCode[i].CodeOffset = 4;
unwindinfo->UnwindCode[i].OpInfo = 7;
i++;
// rsi
unwindinfo->UnwindCode[i].UnwindOp = UWOP_PUSH_NONVOL;
unwindinfo->UnwindCode[i].CodeOffset = 3;
unwindinfo->UnwindCode[i].OpInfo = 6;
i++;
}
else {
unwindinfo->UnwindCode[i].UnwindOp = UWOP_ALLOC_SMALL;
unwindinfo->UnwindCode[i].CodeOffset = 44;
unwindinfo->UnwindCode[i].OpInfo = 3; // (3 + 1) * 8 = 0x20
i++;
for (x = 0; x < ARRAYSIZE(regs1); x++) {
unwindinfo->UnwindCode[x + i].UnwindOp = UWOP_PUSH_NONVOL;
unwindinfo->UnwindCode[x + i].CodeOffset = 14 - (2 * x);
unwindinfo->UnwindCode[x + i].OpInfo = regs1[x];
}
i += x;
for (x = 0; x < ARRAYSIZE(regs2); x++) {
unwindinfo->UnwindCode[x + i].UnwindOp = UWOP_PUSH_NONVOL;
unwindinfo->UnwindCode[x + i].CodeOffset = 6 - x;
unwindinfo->UnwindCode[x + i].OpInfo = regs2[x];
}
i += x;
}
unwindinfo->UnwindCode[i].UnwindOp = UWOP_ALLOC_SMALL;
unwindinfo->UnwindCode[i].CodeOffset = 1;
unwindinfo->UnwindCode[i].OpInfo = 0; // (0 + 1) * 8 = 8
i++;
unwindinfo->CountOfCodes = i;
RtlAddFunctionTable(functable, 1, (DWORD64)h->hookdata);
}
// this function constructs the so-called pre-trampoline, this pre-trampoline
// determines if a hook should really be executed. An example will be the
// easiest; imagine we have a hook on CreateProcessInternalW() and on
// NtCreateProcessEx() (this is actually the case currently), now, if all goes
// well, a call to CreateProcess() will call CreateProcessInternalW() followed
// by a call to NtCreateProcessEx(). Because we already hook the higher-level
// API CreateProcessInternalW() it is not really useful to us to log the
// information retrieved in the NtCreateProcessEx() function as well,
// therefore, because one is called by the other, we can tell the hooking
// engine "once inside a hook, don't hook further API calls" by setting the
// allow_hook_recursion flag to false. The example above is what happens when
// the hook recursion is not allowed.
static void hook_create_pre_tramp(hook_t *h)
{
unsigned char *p;
unsigned int off;
unsigned char pre_tramp1[] = {
// pushfq
0x9c,
// cld
0xfc,
// push rax/rcx/rdx/rbx
0x50, 0x51, 0x52, 0x53,
// push r8, r9, r10, r11
0x41, 0x50, 0x41, 0x51, 0x41, 0x52, 0x41, 0x53,
// call $+0
0xe8, 0x00, 0x00, 0x00, 0x00,
// pop r8
0x41, 0x58,
// sub r8, 19
0x49, 0x83, 0xe8, 0x13,
// mov r8, qword ptr [rsp+0x48]
// 0x4c, 0x8b, 0x44, 0x24, 0x48,
// lea rdx, [rsp+0x48]
0x48, 0x8d, 0x54, 0x24, 0x48,
// mov rcx, h
0x48, 0xb9, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
// 40
unsigned char pre_tramp12[] = {
// sub rsp, 0x20
0x48, 0x83, 0xec, 0x20,
// call enter_hook, returns 0 if we should call the original func, otherwise 1 if we should call our New_ version
0xff, 0x15, 0x02, 0x00, 0x00, 0x00,
// jmp $+8
0xeb, 0x08,
// address of enter_hook
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
unsigned char pre_tramp2[] = {
// test eax, eax
0x85, 0xc0,
// jnz 0x1f
0x75, 0x1f,
// add rsp, 0x20
0x48, 0x83, 0xc4, 0x20,
// pop r11, r10, r9, r8
0x41, 0x5b, 0x41, 0x5a, 0x41, 0x59, 0x41, 0x58,
// pop rbx/rdx/rcx/rax
0x5b, 0x5a, 0x59, 0x58,
// popfq
0x9d,
// jmp h->tramp (original function)
0xff, 0x25, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
unsigned char pre_tramp3[] = {
// add rsp, 0x20
0x48, 0x83, 0xc4, 0x20,
// pop r11, r10, r9, r8
0x41, 0x5b, 0x41, 0x5a, 0x41, 0x59, 0x41, 0x58,
// pop rbx/rdx/rcx/rax
0x5b, 0x5a, 0x59, 0x58,
// popfq
0x9d,
// jmp h->new_func (New_ func)
0xff, 0x25, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
if (disable_this_hook(h)) {
memcpy(h->hookdata->pre_tramp, "\xff\x25\x00\x00\x00\x00", 6);
*(ULONG_PTR *)(h->hookdata->pre_tramp + 6) = (ULONG_PTR)h->hookdata->tramp;
return;
}
p = h->hookdata->pre_tramp;
off = sizeof(pre_tramp1) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp1 + off) = (ULONG_PTR)h;
memcpy(p, pre_tramp1, sizeof(pre_tramp1));
p += sizeof(pre_tramp1);
off = sizeof(pre_tramp12) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp12 + off) = (ULONG_PTR)&enter_hook;
memcpy(p, pre_tramp12, sizeof(pre_tramp12));
p += sizeof(pre_tramp12);
off = sizeof(pre_tramp2) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp2 + off) = (ULONG_PTR)h->hookdata->tramp;
memcpy(p, pre_tramp2, sizeof(pre_tramp2));
p += sizeof(pre_tramp2);
off = sizeof(pre_tramp3) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp3 + off) = (ULONG_PTR)h->new_func;
memcpy(p, pre_tramp3, sizeof(pre_tramp3));
p += sizeof(pre_tramp3);
assert((ULONG_PTR)(p - h->hookdata->pre_tramp) < MAX_PRETRAMP_SIZE);
/* now add the necessary unwind information so that stack traces at enter_hook work
* properly. must be modified whenever the assembly above changes
*/
add_unwind_info(h);
}
static void hook_create_pre_tramp_notail(hook_t *h)
{
unsigned char *p;
unsigned int off;
unsigned char pre_tramp1[] = {
// pushfq
0x9c,
// cld
0xfc,
// push rsi/rdi
0x56, 0x57,
// push rax/rcx/rdx/rbx
0x50, 0x51, 0x52, 0x53,
// push r8, r9, r10, r11
0x41, 0x50, 0x41, 0x51, 0x41, 0x52, 0x41, 0x53,
// call $+0
0xe8, 0x00, 0x00, 0x00, 0x00,
// pop r8
0x41, 0x58,
// sub r8, 0x15
0x49, 0x83, 0xe8, 0x15,
// lea rdx, [rsp+0x58]
0x48, 0x8d, 0x54, 0x24, 0x58,
// mov rcx, h
0x48, 0xb9, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
unsigned char pre_tramp12[] = {
// sub rsp, 0x20
0x48, 0x83, 0xec, 0x20,
// call enter_hook, returns 0 if we should call the original func, otherwise 1 if we should call our New_ version
0xff, 0x15, 0x02, 0x00, 0x00, 0x00,
// jmp $+8
0xeb, 0x08,
// address of enter_hook
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
unsigned char pre_tramp2[] = {
// test eax, eax
0x85, 0xc0,
// jnz 0x21
0x75, 0x21,
// add rsp, 0x20
0x48, 0x83, 0xc4, 0x20,
// pop r11, r10, r9, r8
0x41, 0x5b, 0x41, 0x5a, 0x41, 0x59, 0x41, 0x58,
// pop rbx/rdx/rcx/rax
0x5b, 0x5a, 0x59, 0x58,
// pop rdi/rsi
0x5f, 0x5e,
// popfq
0x9d,
// jmp h->tramp (original function)
0xff, 0x25, 0x00, 0x00, 0x00, 0x00,
// address of original function
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
unsigned char pre_tramp3_nostack[] = {
// mov rcx, [rsp+0x50]
0x48, 0x8b, 0x4c, 0x24, 0x50,
// mov rdx, [rsp+0x48]
0x48, 0x8b, 0x54, 0x24, 0x48,
// mov r8, [rsp+0x38]
0x4c, 0x8b, 0x44, 0x24, 0x38,
// mov r9, [rsp+0x30]
0x4c, 0x8b, 0x4c, 0x24, 0x30,
// 112
// call h->new_func (New_ func)
0xff, 0x15, 0x02, 0x00, 0x00, 0x00,
// jmp $+8
0xeb, 0x08,
// address of new function
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
unsigned char pre_tramp3_stack[] = {
// mov ecx, numargs
0xb9, h->numargs, 0x00, 0x00, 0x00,
// sub ecx, 0x4
0x83, 0xe9, 0x04,
// mov eax, ecx
0x89, 0xc8,
// lea rsi, [rsp+0xa0]
0x48, 0x8d, 0xb4, 0x24, 0xa0, 0x00, 0x00, 0x00,
// shl eax, 3
0xc1, 0xe0, 0x03,
// mov r10, [rsp+0x50], this is RCX, we're storing it in a temp reg for now
0x4c, 0x8b, 0x54, 0x24, 0x50,
// mov rdx, [rsp+0x48]
0x48, 0x8b, 0x54, 0x24, 0x48,
// mov r8, [rsp+0x38]
0x4c, 0x8b, 0x44, 0x24, 0x38,
// mov r9, [rsp+0x30]
0x4c, 0x8b, 0x4c, 0x24, 0x30,
// test eax, 8
0xa9, 0x08, 0x00, 0x00, 0x00,
// jz $+0x4
0x74, 0x04,
// sub rsp, 8
0x48, 0x83, 0xec, 0x08,
// sub rsp, rax
0x48, 0x29, 0xc4,
// mov rdi, rsp
0x48, 0x89, 0xe7,
// repne movsq
0xf2, 0x48, 0xa5,
// mov rcx, r10
0x4c, 0x89, 0xd1,
// sub rsp, 0x20
0x48, 0x83, 0xec, 0x20,
// call h->new_func (New_ func)
0xff, 0x15, 0x02, 0x00, 0x00, 0x00,
// jmp $+8
0xeb, 0x08,
// address of new function
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
unsigned char pre_tramp4_nostack[] = {
// test eax, eax
0x85, 0xc0,
// jnz 0x21
0x75, 0x21,
// add rsp, 0x20 (from pre_tramp12)
0x48, 0x83, 0xc4, 0x20,
// pop r11, r10, r9, r8
0x41, 0x5b, 0x41, 0x5a, 0x41, 0x59, 0x41, 0x58,
// pop rbx/rdx/rcx/rax
0x5b, 0x5a, 0x59, 0x58,
// pop rdi/rsi
0x5f, 0x5e,
// popfq
0x9d,
// jmp h->tramp (original function)
0xff, 0x25, 0x00, 0x00, 0x00, 0x00,
// address of original function
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
unsigned char pre_tramp4_stack[] = {
// test eax, eax
0x85, 0xc0,
// jnz 0x3c
0x75, 0x3c,
// mov eax, numargs
0xb8, h->numargs, 0x00, 0x00, 0x00,
// sub eax, 0x4
0x83, 0xe8, 0x04,
// shl eax, 3
0xc1, 0xe0, 0x03,
// test eax, 8
0xa9, 0x08, 0x00, 0x00, 0x00,
// jz $+0x3
0x74, 0x03,
// add eax, 8
0x83, 0xc0, 0x08,
// add eax, 0x20
0x83, 0xc0, 0x20,
// add rsp, rax
0x48, 0x01, 0xc4,
// add rsp, 0x20 (from pre_tramp12)
0x48, 0x83, 0xc4, 0x20,
// pop r11, r10, r9, r8
0x41, 0x5b, 0x41, 0x5a, 0x41, 0x59, 0x41, 0x58,
// pop rbx/rdx/rcx/rax
0x5b, 0x5a, 0x59, 0x58,
// pop rdi/rsi
0x5f, 0x5e,
// popfq
0x9d,
// jmp h->tramp (original function)
0xff, 0x25, 0x00, 0x00, 0x00, 0x00,
// address of original function
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
unsigned char pre_tramp5_nostack[] = {
// add rsp, 0x20 (from pre_tramp12)
0x48, 0x83, 0xc4, 0x20,
// pop r11, r10, r9, r8
0x41, 0x5b, 0x41, 0x5a, 0x41, 0x59, 0x41, 0x58,
// pop rbx/rdx/rcx/rax
0x5b, 0x5a, 0x59, 0x58,
// pop rdi/rsi
0x5f, 0x5e,
// popfq
0x9d,
// jmp h->alt_func
0xff, 0x25, 0x00, 0x00, 0x00, 0x00,
// address of alternate function
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
unsigned char pre_tramp5_stack[] = {
// mov eax, numargs
0xb8, h->numargs, 0x00, 0x00, 0x00,
// sub eax, 0x4
0x83, 0xe8, 0x04,
// shl eax, 3
0xc1, 0xe0, 0x03,
// test eax, 8
0xa9, 0x08, 0x00, 0x00, 0x00,
// jz $+0x3
0x74, 0x03,
// add eax, 8
0x83, 0xc0, 0x08,
// add eax, 0x20
0x83, 0xc0, 0x20,
// add rsp, rax
0x48, 0x01, 0xc4,
// add rsp, 0x20 (from pre_tramp12)
0x48, 0x83, 0xc4, 0x20,
// pop r11, r10, r9, r8
0x41, 0x5b, 0x41, 0x5a, 0x41, 0x59, 0x41, 0x58,
// pop rbx/rdx/rcx/rax
0x5b, 0x5a, 0x59, 0x58,
// pop rdi/rsi
0x5f, 0x5e,
// popfq
0x9d,
// jmp h->alt_func
0xff, 0x25, 0x00, 0x00, 0x00, 0x00,
// address of alternate function
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
if (disable_this_hook(h)) {
memcpy(h->hookdata->pre_tramp, "\xff\x25\x00\x00\x00\x00", 6);
*(ULONG_PTR *)(h->hookdata->pre_tramp + 6) = (ULONG_PTR)h->hookdata->tramp;
return;
}
p = h->hookdata->pre_tramp;
off = sizeof(pre_tramp1) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp1 + off) = (ULONG_PTR)h;
memcpy(p, pre_tramp1, sizeof(pre_tramp1));
p += sizeof(pre_tramp1);
off = sizeof(pre_tramp12) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp12 + off) = (ULONG_PTR)&enter_hook;
memcpy(p, pre_tramp12, sizeof(pre_tramp12));
p += sizeof(pre_tramp12);
off = sizeof(pre_tramp2) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp2 + off) = (ULONG_PTR)h->hookdata->tramp;
memcpy(p, pre_tramp2, sizeof(pre_tramp2));
p += sizeof(pre_tramp2);
if (h->numargs > 4) {
off = sizeof(pre_tramp3_stack) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp3_stack + off) = (ULONG_PTR)h->new_func;
memcpy(p, pre_tramp3_stack, sizeof(pre_tramp3_stack));
p += sizeof(pre_tramp3_stack);
off = sizeof(pre_tramp4_stack) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp4_stack + off) = (ULONG_PTR)h->hookdata->tramp;
memcpy(p, pre_tramp4_stack, sizeof(pre_tramp4_stack));
p += sizeof(pre_tramp4_stack);
off = sizeof(pre_tramp5_stack) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp5_stack + off) = (ULONG_PTR)h->alt_func;
memcpy(p, pre_tramp5_stack, sizeof(pre_tramp5_stack));
p += sizeof(pre_tramp5_stack);
}
else {
off = sizeof(pre_tramp3_nostack) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp3_nostack + off) = (ULONG_PTR)h->new_func;
memcpy(p, pre_tramp3_nostack, sizeof(pre_tramp3_nostack));
p += sizeof(pre_tramp3_nostack);
off = sizeof(pre_tramp4_nostack) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp4_nostack + off) = (ULONG_PTR)h->hookdata->tramp;
memcpy(p, pre_tramp4_nostack, sizeof(pre_tramp4_nostack));
p += sizeof(pre_tramp4_nostack);
off = sizeof(pre_tramp5_nostack) - sizeof(ULONG_PTR);
*(ULONG_PTR *)(pre_tramp5_nostack + off) = (ULONG_PTR)h->alt_func;
memcpy(p, pre_tramp5_nostack, sizeof(pre_tramp5_nostack));
p += sizeof(pre_tramp5_nostack);
}
assert((ULONG_PTR)(p - h->hookdata->pre_tramp) < MAX_PRETRAMP_SIZE);
/* now add the necessary unwind information so that stack traces at enter_hook work
* properly. must be modified whenever the assembly above changes
*/
add_unwind_info(h);
}
static int hook_api_jmp_indirect(hook_t *h, unsigned char *from,
unsigned char *to)
{
// jmp dword [hook_data]
*from++ = 0xff;
*from++ = 0x25;
*(int *)from = (int)((ULONG_PTR)h->hookdata->hook_data - ((ULONG_PTR)from + 4));
// the real address is stored in hook_data
memcpy(h->hookdata->hook_data, &to, sizeof(to));
return 0;
}
static int hook_api_native_jmp_indirect(hook_t *h, unsigned char *from,
unsigned char *to)
{
// hook used for Native API functions where the second instruction specifies the syscall number
// we'll leave in that mov instruction and repeat it before calling the original function
from += 8;
return hook_api_jmp_indirect(h, from, to);
}
hook_data_t *alloc_hookdata_near(void *addr)
{
PVOID BaseAddress;
int offset = -(1024 * 1024 * 1024);
SIZE_T RegionSize = sizeof(hook_data_t);
LONG status;
do {
if (offset < 0 && (ULONG_PTR)addr < (ULONG_PTR)-offset)
offset = 0x10000;
BaseAddress = (PCHAR)addr + offset;
status = pNtAllocateVirtualMemory(GetCurrentProcess(), &BaseAddress, 0, &RegionSize, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
if (status >= 0)
return (hook_data_t *)BaseAddress;
offset += 0x10000;
} while (status < 0 && offset <= (1024 * 1024 * 1024));
return NULL;
}
unsigned char *handle_stub(hook_t *h, unsigned char *addr)
{
unsigned char stack_offset = 0;
unsigned char *p = addr;
unsigned char *new_addr = NULL;
int found_call = 0;
while (*p != 0xc3 && *p != 0xe9 && *p != 0xeb) {
if (!memcmp(p, "\x48\x83\xec", 3)) {
if (stack_offset)
goto out;
stack_offset = p[3];
p += 4;
}
else if (!memcmp(p, "\x48\x8b\x44\x24", 4))
p += 5;
else if (!memcmp(p, "\x48\x8b\x84\x24", 4))
p += 8;
else if (!memcmp(p, "\x8b\x44\x24", 3))
p += 4;
else if (!memcmp(p, "\x8b\x84\x24", 3))
p += 7;
else if (!memcmp(p, "\x48\x89\x44\x24", 4))
p += 5;
else if (!memcmp(p, "\x89\x44\x24", 3))
p += 4;
else if (!memcmp(p, "\x48\x83\xc4", 3)) {
if (!stack_offset || *(unsigned char *)&p[3] != stack_offset)
goto out;
p += 4;
}
else if (p[0] == 0xe8) {
unsigned char *target;
target = (unsigned char *)get_near_rel_target(p);
if (target[0] != 0xff || target[1] != 0x25)
goto out;
new_addr = (unsigned char *)get_indirect_target(target);
found_call = 1;
p += 5;
}
else
goto out;
}
if (new_addr)
return new_addr;
out:
return addr;
}
int hook_api(hook_t *h, int type)
{
DWORD old_protect;
int ret = -1;
unsigned char *addr;
// table with all possible hooking types
static struct {
int(*hook)(hook_t *h, unsigned char *from, unsigned char *to);
int len;
} hook_types[] = {
/* HOOK_NATIVE_JMP_INDIRECT */{ &hook_api_native_jmp_indirect, 14 },
/* HOOK_JMP_INDIRECT */{ &hook_api_jmp_indirect, 6 },
};
// is this address already hooked?
if (h->is_hooked != 0) {
return 0;
}
if (hook_is_excluded(h))
return 0;
// resolve the address to hook
addr = h->addr;
if (addr == NULL && h->library != NULL && h->funcname != NULL) {
HMODULE hmod = GetModuleHandleW(h->library);
/* if the DLL isn't loaded, don't bother attempting anything else */
if (hmod == NULL)
return 0;
if (!strcmp(h->funcname, "RtlDispatchException")) {
// RtlDispatchException is the first relative call in KiUserExceptionDispatcher
unsigned char *baseaddr = (unsigned char *)GetProcAddress(hmod, "KiUserExceptionDispatcher");
int instroff = 0;
while (baseaddr[instroff] != 0xe8) {
instroff += lde(&baseaddr[instroff]);
}
addr = (unsigned char *)get_near_rel_target(&baseaddr[instroff]);
}
else if (!wcscmp(h->library, L"kernel32") && !strcmp(h->funcname, "MoveFileWithProgressTransactedW")) {
unsigned char *tmpaddr = (unsigned char *)GetProcAddress(hmod, "MoveFileWithProgressW");
if (tmpaddr[18] == 0xe8 && tmpaddr[27] == 0xc3) {
addr = (unsigned char *)get_near_rel_target(tmpaddr + 18);
} else
addr = (unsigned char *)GetProcAddress(hmod, h->funcname);
}
else if (!strcmp(h->funcname, "JsEval"))
addr = (unsigned char *)get_jseval_addr(hmod);
else if (!strcmp(h->funcname, "COleScript_ParseScriptText"))
addr = (unsigned char *)get_olescript_parsescripttext_addr(hmod);
else if (!strcmp(h->funcname, "CDocument_write"))
addr = (unsigned char *)get_cdocument_write_addr(hmod);
else
addr = (unsigned char *)GetProcAddress(hmod, h->funcname);
}
if (addr == NULL) {
// function doesn't exist in this DLL, not a critical error
return 0;
}
addr = handle_stub(h, addr);
if (addr[0] == 0xeb) {
PUCHAR target = (PUCHAR)get_short_rel_target(addr);
if (target[0] == 0xff && target[1] == 0x25) {
PUCHAR origaddr = addr;
addr = (PUCHAR)get_indirect_target(target);
// handle delay-loaded DLL stubs
if (!memcmp(addr, "\x48\x8d\x05", 3) && addr[7] == 0xe9) {
// skip this particular hook, we'll hook the delay-loaded DLL at the time
// is is loaded. This means we will have duplicate "hook" entries
// but to avoid any problems, we will check before hooking to see
// if the final function has already been hooked
return 0;
}
}
}
else if (addr[0] == 0xe9) {
PUCHAR target = (PUCHAR)get_near_rel_target(addr);
unhook_detect_add_region(h, addr, addr, addr, 5);
if (target[0] == 0xff && target[1] == 0x25) {
addr = (PUCHAR)get_indirect_target(target);
// handle delay-loaded DLL stubs
if (!memcmp(addr, "\x48\x8d\x05", 3) && addr[7] == 0xe9) {
// skip this particular hook, we'll hook the delay-loaded DLL at the time
// is is loaded. This means we will have duplicate "hook" entries
// but to avoid any problems, we will check before hooking to see
// if the final function has already been hooked
return 0;
}
}
else {
addr = target;
}
}
addr = handle_stub(h, addr);
/*
if (!wcscmp(h->library, L"ntdll") && !memcmp(addr, "\x4c\x8b\xd1\xb8", 4)) {
// hooking a native API, leave in the mov eax, <syscall nr> instruction
// as some malware depends on this for direct syscalls
// missing a few syscalls is better than crashing and getting no information
// at all
type = HOOK_NATIVE_JMP_INDIRECT;
}
*/