cea-sec/miasmFramework de engenharia reversa em Python
Miasm é um framework de engenharia reversa gratuito e de código aberto (GPLv2). O Miasm visa analisar / modificar / gerar programas binários. Aqui está uma lista não exaustiva de funcionalidades:
Veja o blog oficial para mais exemplos e demonstrações.
Importar arquitetura x86 do Miasm:```pycon
from miasm.arch.x86.arch import mn_x86 from miasm.core.locationdb import LocationDB
Obter um banco de dados de localização:```pycon
>>> loc_db = LocationDB()
Monte uma linha:```pycon
l = mn_x86.fromstring('XOR ECX, ECX', loc_db, 32) print(l) XOR ECX, ECX mn_x86.asm(l) ['1\xc9', '3\xc9', 'g1\xc9', 'g3\xc9']
Modificar um operando:```pycon
>>> l.args[0] = mn_x86.regs.EAX
>>> print(l)
XOR EAX, ECX
>>> a = mn_x86.asm(l)
>>> print(a)
['1\xc8', '3\xc1', 'g1\xc8', 'g3\xc1']
Desmonte o resultado:```pycon
print(mn_x86.dis(a[0], 32)) XOR EAX, ECX
Usando abstração `Machine`:```pycon
>>> from miasm.analysis.machine import Machine
>>> mn = Machine('x86_32').mn
>>> print(mn.dis('\x33\x30', 32))
XOR ESI, DWORD PTR [EAX]
Para MIPS:```pycon
mn = Machine('mips32b').mn print(mn.dis(b'\x97\xa3\x00 ', "b")) LHU V1, 0x20(SP)
Representação intermediária
---------------------------
Criar uma instrução:```pycon
>>> machine = Machine('arml')
>>> instr = machine.mn.dis('\x00 \x88\xe0', 'l')
>>> print(instr)
ADD R2, R8, R0
Crie um objeto de representação intermediária:```pycon
lifter = machine.lifter_model_call(loc_db)
Crie um ircfg vazio:```pycon
>>> ircfg = lifter.new_ircfg()
Adicionar instrução ao pool:```pycon
lifter.add_instr_to_ircfg(instr, ircfg)
Exibir pool atual:```pycon
>>> for lbl, irblock in ircfg.blocks.items():
... print(irblock)
loc_0:
R2 = R8 + R0
IRDst = loc_4
Trabalhando com IR, por exemplo obtendo efeitos colaterais:```pycon
for lbl, irblock in ircfg.blocks.items(): ... for assignblk in irblock: ... rw = assignblk.get_rw() ... for dst, reads in rw.items(): ... print('read: ', [str(x) for x in reads]) ... print('written:', dst) ... print() ... read: ['R8', 'R0'] written: R2
read: [] written: IRDst
Mais informações sobre o Miasm IR estão no [Jupyter Notebook correspondente](https://github.com/cea-sec/miasm/blob/master/doc/expression/expression.ipynb).
Emulação
---------```pycon
00000000 8d4904 lea ecx, [ecx+0x4]
00000003 8d5b01 lea ebx, [ebx+0x1]
00000006 80f901 cmp cl, 0x1
00000009 7405 jz 0x10
0000000b 8d5bff lea ebx, [ebx-1]
0000000e eb03 jmp 0x13
00000010 8d5b01 lea ebx, [ebx+0x1]
00000013 89d8 mov eax, ebx
00000015 c3 ret
>>> s = b'\x8dI\x04\x8d[\x01\x80\xf9\x01t\x05\x8d[\xff\xeb\x03\x8d[\x01\x89\xd8\xc3'
Importe o shellcode graças à abstração Container:```pycon
from miasm.analysis.binary import Container c = Container.from_string(s, loc_db) c <miasm.analysis.binary.ContainerUnknown object at 0x7f34cefe6090>
Desmontando o shellcode no endereço `0`:```pycon
>>> from miasm.analysis.machine import Machine
>>> machine = Machine('x86_32')
>>> mdis = machine.dis_engine(c.bin_stream, loc_db=loc_db)
>>> asmcfg = mdis.dis_multiblock(0)
>>> for block in asmcfg.blocks:
... print(block)
...
loc_0
LEA ECX, DWORD PTR [ECX + 0x4]
LEA EBX, DWORD PTR [EBX + 0x1]
CMP CL, 0x1
JZ loc_10
-> c_next:loc_b c_to:loc_10
loc_10
LEA EBX, DWORD PTR [EBX + 0x1]
-> c_next:loc_13
loc_b
LEA EBX, DWORD PTR [EBX + 0xFFFFFFFF]
JMP loc_13
-> c_to:loc_13
loc_13
MOV EAX, EBX
RET
Inicializando o mecanismo JIT com uma pilha:```pycon
jitter = machine.jitter(loc_db, jit_type='python') jitter.init_stack()
Adicione o shellcode em um local de memória arbitrário:```pycon
>>> run_addr = 0x40000000
>>> from miasm.jitter.csts import PAGE_READ, PAGE_WRITE
>>> jitter.vm.add_memory_page(run_addr, PAGE_READ | PAGE_WRITE, s)
Crie uma sentinelle para capturar o retorno do shellcode:```Python def code_sentinelle(jitter): jitter.running = False jitter.pc = 0 return True
jitter.add_breakpoint(0x1337beef, code_sentinelle) jitter.push_uint32_t(0x1337beef)
Registos ativos:```pycon
>>> jitter.set_trace_log()
Executar em endereço arbitrário:```pycon
jitter.init_run(run_addr) jitter.continue_run() RAX 0000000000000000 RBX 0000000000000000 RCX 0000000000000000 RDX 0000000000000000 RSI 0000000000000000 RDI 0000000000000000 RSP 000000000123FFF8 RBP 0000000000000000 zf 0000000000000000 nf 0000000000000000 of 0000000000000000 cf 0000000000000000 RIP 0000000040000000 40000000 LEA ECX, DWORD PTR [ECX+0x4] RAX 0000000000000000 RBX 0000000000000000 RCX 0000000000000004 RDX 0000000000000000 RSI 0000000000000000 RDI 0000000000000000 RSP 000000000123FFF8 RBP 0000000000000000 zf 0000000000000000 nf 0000000000000000 of 0000000000000000 cf 0000000000000000 .... 4000000e JMP loc_0000000040000013:0x40000013 RAX 0000000000000000 RBX 0000000000000000 RCX 0000000000000004 RDX 0000000000000000 RSI 0000000000000000 RDI 0000000000000000 RSP 000000000123FFF8 RBP 0000000000000000 zf 0000000000000000 nf 0000000000000000 of 0000000000000000 cf 0000000000000000 RIP 0000000040000013 40000013 MOV EAX, EBX RAX 0000000000000000 RBX 0000000000000000 RCX 0000000000000004 RDX 0000000000000000 RSI 0000000000000000 RDI 0000000000000000 RSP 000000000123FFF8 RBP 0000000000000000 zf 0000000000000000 nf 0000000000000000 of 0000000000000000 cf 0000000000000000 RIP 0000000040000013 40000015 RET
Interagindo com o jitter:```pycon
>>> jitter.vm
ad 1230000 size 10000 RW_ hpad 0x2854b40
ad 40000000 size 16 RW_ hpad 0x25e0ed0