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
|
#! /usr/bin/env python
# test instruction caching
from miasm2.core.cpu import parse_ast
from miasm2.arch.x86.arch import mn_x86, base_expr, variable
from miasm2.core.bin_stream import bin_stream
from miasm2.core import parse_asm
from miasm2.expression.expression import *
from elfesteem import *
from pdb import pm
from miasm2.core import asmbloc
import struct
e = pe_init.PE()
s_text = e.SHList.add_section(name="text", addr=0x1000, rawsize=0x1000)
s_iat = e.SHList.add_section(name="iat", rawsize=0x100)
new_dll = [({"name": "USER32.dll",
"firstthunk": s_iat.addr}, ["MessageBoxA"])]
e.DirImport.add_dlldesc(new_dll)
s_myimp = e.SHList.add_section(name="myimp", rawsize=len(e.DirImport))
e.DirImport.set_rva(s_myimp.addr)
reg_and_id = dict(mn_x86.regs.all_regs_ids_byname)
def my_ast_int2expr(a):
return ExprInt32(a)
def my_ast_id2expr(t):
return reg_and_id.get(t, ExprId(t, size=32))
my_var_parser = parse_ast(my_ast_id2expr, my_ast_int2expr)
base_expr.setParseAction(my_var_parser)
blocs, symbol_pool = parse_asm.parse_txt(mn_x86, 32, '''
main:
CALL test_automod
RET
lbl_good:
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
test_automod:
PUSH EBP
MOV EBP, ESP
LEA EDI, DWORD PTR [lbl_mod]
LEA ESI, DWORD PTR [lbl_good]
MOV ECX, 0x8
REPE MOVSB
lbl_mod:
XOR EAX, EAX
MOV DWORD PTR [EAX], 0xDEADC0DE
NOP
NOP
NOP
PUSH 0
PUSH title
PUSH msg
PUSH 0
CALL DWORD PTR [ MessageBoxA ]
MOV ESP, EBP
POP EBP
RET
title:
.string "Hello!"
msg:
.string "World!"
''')
# fix shellcode addr
symbol_pool.set_offset(symbol_pool.getby_name("main"), e.rva2virt(s_text.addr))
symbol_pool.set_offset(symbol_pool.getby_name_create("MessageBoxA"),
e.DirImport.get_funcvirt('MessageBoxA'))
e.Opthdr.AddressOfEntryPoint = s_text.addr
for b in blocs[0]:
print b
resolved_b, patches = asmbloc.asm_resolve_final(
mn_x86, 32, blocs[0], symbol_pool)
print patches
for offset, raw in patches.items():
e.virt[offset] = raw
open('box_x86_32_repmod.bin', 'wb').write(str(e))
|