LyScript 自实现汇编搜索功能

2022-12-28 18:23:19 浏览数 (1)

通过对LyScript自动化插件进行二次封装,实现从内存中读入目标进程解码后的机器码,并通过Python代码在这些机器码中寻找特定的十六进制字符数组,或直接检索是否存在连续的反汇编指令片段等功能。

  • 插件地址:https://github.com/lyshark/LyScript

搜索内存中的机器码: 内存机器码需要配合LyScript32插件,从内存中寻找指令片段。

代码语言:javascript复制
from LyScript32 import MyDebug

# 将可执行文件中的单数转换为 0x00 格式
def ReadHexCode(code):
    hex_code = []

    for index in code:
        if index >= 0 and index <= 15:
            #print("0"   str(hex(index).replace("0x","")))
            hex_code.append("0"   str(hex(index).replace("0x","")))
        else:
            hex_code.append(hex(index).replace("0x",""))
            #print(hex(index).replace("0x",""))

    return hex_code

# 获取到内存中的机器码
def GetCode():
    try:
        ref_code = []
        dbg = MyDebug()
        connect_flag = dbg.connect()
        if connect_flag != 1:
            return None

        start_address = dbg.get_local_base()
        end_address = start_address   dbg.get_local_size()

        # 循环得到机器码
        for index in range(start_address,end_address):
            read_bytes = dbg.read_memory_byte(index)
            ref_code.append(read_bytes)

        dbg.close()
        return ref_code
    except Exception:
        return False

# 在字节数组中匹配是否与特征码一致
def SearchHexCode(Code,SearchCode,ReadByte):
    SearchCount = len(SearchCode)
    #print("特征码总长度: {}".format(SearchCount))
    for item in range(0,ReadByte):
        count = 0
        # 对十六进制数切片,每次向后遍历SearchCount
        OpCode = Code[ 0 item :SearchCount item ]
        #print("切割数组: {} --> 对比: {}".format(OpCode,SearchCode))
        try:
            for x in range(0,SearchCount):
                if OpCode[x] == SearchCode[x]:
                    count = count   1
                    #print("寻找特征码计数: {} {} {}".format(count,OpCode[x],SearchCode[x]))
                    if count == SearchCount:
                        # 如果找到了,就返回True,否则返回False
                        return True
                        exit(0)
        except Exception:
            pass
    return False

if __name__ == "__main__":
    # 读取到内存机器码
    ref_code = GetCode()
    if ref_code != False:
        # 转为十六进制
        hex_code = ReadHexCode(ref_code)
        code_size = len(hex_code)

        # 指定要搜索的特征码序列
        search = ['c0', '74', '0d', '66', '3b', 'c6', '77', '08']

        # 搜索特征: hex_code = exe的字节码,search=搜索特征码,code_size = 搜索大小
        ret = SearchHexCode(hex_code, search, code_size)
        if ret == True:
            print("特征码 {} 存在".format(search))
        else:
            print("特征码 {} 不存在".format(search))
    else:
        print("读入失败")

输出效果:

搜索内存反汇编代码: 通过LyScript插件读入内存机器码,并在该机器码中寻找指令片段,找到后返回内存首地址。

代码语言:javascript复制
from LyScript32 import MyDebug

# 检索指定序列中是否存在一段特定的指令集
def SearchOpCode(OpCodeList,SearchCode,ReadByte):
    SearchCount = len(SearchCode)
    for item in range(0,ReadByte):
        count = 0
        OpCode_Dic = OpCodeList[ 0   item : SearchCount   item ]
        # print("切割字典: {}".format(OpCode_Dic))
        try:
            for x in range(0,SearchCount):
                if OpCode_Dic[x].get("opcode") == SearchCode[x]:
                    #print(OpCode_Dic[x].get("addr"),OpCode_Dic[x].get("opcode"))
                    count = count   1
                    if count == SearchCount:
                        #print(OpCode_Dic[0].get("addr"))
                        return OpCode_Dic[0].get("addr")
                        exit(0)
        except Exception:
            pass

if __name__ == "__main__":
    dbg = MyDebug()
    connect_flag = dbg.connect()
    print("连接状态: {}".format(connect_flag))

    # 得到EIP位置
    eip = dbg.get_register("eip")

    # 反汇编前1000行
    disasm_dict = dbg.get_disasm_code(eip,1000)

    # 搜索一个指令序列,用于快速查找构建漏洞利用代码
    SearchCode = [
        ["push 0xC0000409", "call 0x003F1B38", "pop ecx"],
        ["push ecx", "push ebx"]
    ]

    # 检索内存指令集
    for item in range(0,len(SearchCode)):
        Search = SearchCode[item]
        # disasm_dict = 返回汇编指令 Search = 寻找指令集 1000 = 向下检索长度
        ret = SearchOpCode(disasm_dict,Search,1000)
        if ret != None:
            print("指令集: {} --> 首次出现地址: {}".format(SearchCode[item],hex(ret)))

    dbg.close()

输出效果:

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