61 lines
1.3 KiB
Python
Executable File
61 lines
1.3 KiB
Python
Executable File
#!/usr/bin/python
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from unicorn import *
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from unicorn.x86_const import *
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from capstone import *
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ESP = 0x2000
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PAGE_SIZE = 2 * 1024 * 1024
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# mov [esp], DWORD 0x37f
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# fldcw [esp]
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# fnop
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# fnstenv [esp + 8]
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# pop ecx
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CODE = b'\xc7\x04\x24\x7f\x03\x00\x00\xd9\x2c\x24\xd9\xd0\xd9\x74\x24\x08\x59'
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class SimpleEngine:
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def __init__(self):
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self.capmd = Cs(CS_ARCH_X86, CS_MODE_32)
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def disas_single(self, data):
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for i in self.capmd.disasm(data, 16):
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print("\t%s\t%s" % (i.mnemonic, i.op_str))
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break
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disasm = SimpleEngine()
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def hook_code(uc, addr, size, user_data):
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mem = uc.mem_read(addr, size)
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print(" 0x%X:" % (addr)),
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disasm.disas_single(str(mem))
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def mem_reader(addr, size):
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tmp = mu.mem_read(addr, size)
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for i in tmp:
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print(" 0x%x" % i),
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print("")
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mu = Uc(UC_ARCH_X86, UC_MODE_32)
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mu.mem_map(0x0, PAGE_SIZE)
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mu.mem_write(0x4000, CODE)
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mu.reg_write(UC_X86_REG_ESP, ESP)
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mu.hook_add(UC_HOOK_CODE, hook_code)
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mu.emu_start(0x4000, 0, 0, 5)
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esp = mu.reg_read(UC_X86_REG_ESP)
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print("value at ESP [0x%X - 4]: " % esp)
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mem_reader(esp + 14, 4)
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# EXPECTED OUTPUT:
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# 0x4000: mov dword ptr [esp], 0x37f
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# 0x4007: fldcw word ptr [esp]
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# 0x400A: fnop
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# 0x400C: fnstenv dword ptr [esp + 8]
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# 0x4010: pop ecx
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# value at ESP [0x2004 - 4]:
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# 0x0 0x0 0xa 0x40
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# ^ this value should match the fnop instuction addr |