OD附加功能分析

r囧r小猫 2023-10-12 03:17 18阅读 0赞

**OD版本：OllyICE v1.10**

** **

**在从文件菜单选择附加后，OD会在注册一个窗口类后，先创建一个0x138大小的进程表; 再是CreateWindowExA 创建窗口;**

** **

**00478013 loc\_478013:                            **

**00478013                 push    0               ; int**

**00478015                 push    offset sub\_477C10 ; int**

**0047801A                 push    100h            ; int**

**0047801F                 push    310h            ; int**

**00478024                 push    offset asc\_4C20E8 ; "?**

**00478029                 push    offset byte\_4ED3FC ; dest**

**0047802E                 call    \_Createsorteddata     //此处为创建进程表**

** **

**表的结构体如下：**

**table           struc ; (sizeof=0x138)**

**name            db 260 dup(?)   //表的名字**

**count       dd ?                //表中保存的数据个数**

**maxcount        dd ?           //表能保存的最大数量**

**currentobj      dd ?            //当前选中的表中数据的ID，未选中时为为\-1**

**addrcurobj       dd ?             //当前选中数据的地址，未选中时为0**

**size            dd ?            //表中每个数据的大小**

**field\_118       dd ?**

**baseaddrobj           dd ?      //表中保存的数据的基地址**

**fncmp              dd ?        //函数首地址**

**field\_124       dd ?**

**field\_128      dd ?    **

**sign            dd ?   //标志位，表示是否有索引数据（也就是baseaddroffset是否有效）**

**baseaddroffset        dd ?       //索引数据，标示每个数据在表中的顺序**

**field\_134       dd ?**

**table           ends**

** **

**然后OD会获取自己的进程ID号，并获取EnumProcesses ，EnumProcessModules，GetModuleFileNameExA 三个函数的地址；**

** **

**00475138 loc\_475138:                            **

**00475138                 xor     ebx, ebx**

**0047513A                 call    GetCurrentProcessId  //获取OD本身的进程ID**

**0047513F                 mov     \[ebp+var\_10\], eax**

**00475142                 mov     eax, dword\_4D5A0C**

**00475147                 test    eax, eax**

**00475149                 jz      loc\_4752AF**

**0047514F                 push    offset aEnumprocesses ; "EnumProcesses"**

**00475154                 push    eax             ; hModule**

**00475155                 call    GetProcAddress//获取EnumProcesses地址**

**0047515A                 mov     edi, eax**

**0047515C                 push    offset aEnumprocessm\_0 ; "EnumProcessModules"**

**00475161                 mov     eax, dword\_4D5A0C**

**00475166                 push    eax             ; hModule**

**00475167                 call    GetProcAddress//获取EnumProcessModules的地址**

**0047516C                 mov     \[ebp+var\_20\], eax**

**0047516F                 push    offset aGetmodulefil\_0 ; "GetModuleFileNameExA"**

**00475174                 mov     edx, dword\_4D5A0C**

**0047517A                 push    edx             ; hModule**

**0047517B                 call    GetProcAddress//获取GetModuleFileNameExA地址**

**00475180                 mov     \[ebp+var\_24\], eax**

** **

**之后OD枚举系统中的所有进程并保存枚举到的进程；**

** **

**004751A3                 push    eax**

**004751A4                 push    400h**

**004751A9                 push    edx**

**004751AA                 call    edi   // EnumProcesses  枚举进程**

**004751AC                 test    eax, eax**

**004751AE                 jnz     short loc\_4751B3**

** **

**接着再一个循环中OD会尝试利用OpenProcess打开枚举到的所有进程，如果进程ID不等于OD本身ID 并且OpenProcess函数返回成功的话，OD会利用EnumProcessModules枚举模块并获取第一个模块句柄，如果EnumProcessModules返回成功，OD会利用GetModuleFileNameExA获取模块全路径，最后把进程ID和 模块全路径 按顺序保存到上面建立的 进程表 中； **

** **

**004751DB loc\_4751DB:                             **

**004751DB                 mov     eax, \[edi\]**

**004751DD                 cmp     eax, \[ebp+var\_10\]// 判断是否等于OD本身ID**

**004751E0                 jz      loc\_47529B**

**004751E6                 push    eax             ; dwProcessId**

**004751E7                 push    0               ; bInheritHandle**

**004751E9                 push    410h            ; dwDesiredAccess**

**004751EE                 call    OpenProcess**

**004751F3                 mov     \[ebp+hObject\], eax**

**004751F6                 cmp     \[ebp+hObject\], 0//判断进程是否打开成功**

**004751FA                 jz      loc\_47529B**

**00475200                 lea     edx, \[ebp+var\_C\]**

**00475203                 lea     ecx, \[ebp+var\_1C\]**

**00475206                 push    edx**

**00475207                 push    4**

**00475209                 push    ecx**

**0047520A                 mov     eax, \[ebp+hObject\]**

**0047520D                 push    eax**

**0047520E                 call    \[ebp+var\_20\] //EnumProcessModules枚举进程模块**

**00475211                 test    eax, eax**

**00475213                 jnz     short loc\_475220**

**00475215                 mov     edx, \[ebp+hObject\]**

**00475218                 push    edx             ; hObject**

**00475219                 call    CloseHandle//如果EnumProcessModules不成功则关闭句柄**

**0047521E                 jmp     short loc\_47529B**

** **

**如果EnumProcessModules成功则走如下分支**

** **

**00475220 loc\_475220:                          **

**00475220                 mov     ecx, \[edi\]      ; int**

**00475222                 xor     eax, eax        ; int**

**00475224                 mov     dword ptr \[ebp+arglist\], ecx//把进程ID保存到一临时结构体中**

**0047522A                 lea     edx, \[ebp+var\_528\]**

**00475230                 mov     \[ebp+var\_730\], 1**

**0047523A                 mov     \[ebp+var\_72C\], eax**

**00475240                 mov     \[ebp+var\_528\], 0**

**00475247                 push    104h**

**0047524C                 push    edx**

**0047524D                 mov     ecx, \[ebp+var\_1C\]**

**00475250                 push    ecx**

**00475251                 mov     eax, \[ebp+hObject\]**

**00475254                 push    eax**

**00475255                 call    \[ebp+var\_24\]//GetModuleFileNameExA获得模块路径**

**00475258                 mov     \[ebp+var\_425\], 0**

**0047525F                 mov     edx, \[ebp+hObject\]**

**00475262                 push    edx             ; hObject**

**00475263                 call    CloseHandle//关闭打开的进程句柄**

**00475268                 push    0**

**0047526A                 lea     ecx, \[ebp+var\_728\]**

**00475270                 push    ecx**

**00475271                 push    0**

**00475273                 push    0**

**00475275                 lea     eax, \[ebp+var\_528\]**

**0047527B                 push    eax**

**0047527C                 call    004A51BC   //把模块路径复制到临时变量结构体中**

**00475281                 add     esp, 14h**

**00475284                 lea     edx, \[ebp+arglist\] ; int**

**0047528A                 mov     \[ebp+var\_628\], 0**

**00475291                 push    edx             ; arglist**

**00475292                 push    esi             ; src**

**00475293                 call    \_Addsorteddata //把包含了进程ID与模块路径的临时结构体添加到进程表中**

**00475298                 add     esp, 8**

** **

**0047529B loc\_47529B:                                                               **

**0047529B                 inc     \[ebp+var\_4\]**

**0047529E                 add     edi, 4**

**004752A1                 mov     ecx, \[ebp+var\_4\]**

**004752A4                 cmp     ecx, \[ebp+var\_8\] //检查比较次数是否小于枚举到的进程个数**

**004752A7                 jl      loc\_4751DB //小于则继续循环**

** **

**           **

** **

**枚举完进程后接着检查进程表中保存的数据是否小于等于0；如果小于等于则直接返回；**

**反之则EnumWindows,并利用GetWindowText函数获取桌面窗口的标题**

**保存到 进程表中 对应的进程数据中**

**004753E9              cmp     dword ptr \[esi+104h\], 0//比较进程表中数据是否小于0**

**004753F0              jle     short loc\_4753FD**

**004753F2              push    esi       //此处的参数是 进程表的首地址**

**004753F3              push    offset sub\_477A90 ; lpEnumFunc**

**004753F8              call    EnumWindows**

** **

**以下是EnumWindowsProc的功能**

**00477AA8                 lea     edx, \[ebp+dwProcessId\]**

**00477AAB                 push    edx             ; lpdwProcessId**

**00477AAC                 mov     ecx, \[ebp+hWnd\]**

**00477AAF                 push    ecx        //枚举的窗口进程的句柄**

**00477AB0                 call    GetWindowThreadProcessId //获得窗口的进程ID**

** **

**下面是个循环 利用上面得到的进程ID与进程表中保存的进程ID做比较，如果相等 则GetWindowTextA获得窗口标题，并把得到的数据保存在进程表中对应的位置**

**00477ABB loc\_477ABB:                             ; CODE XREF: sub\_477A90+75j**

**00477ABB                 mov     edx, \[ebx\]**

**00477ABD                 cmp     edx, \[ebp+dwProcessId\]**

**00477AC0                 jnz     short loc\_477AF8**

**00477AC2                 cmp     byte ptr \[ebx+10Ch\], 0**

**00477AC9                 jnz     short loc\_477AF8**

**00477ACB                 push    100h            ; nMaxCount**

**00477AD0                 mov     ecx, eax**

**00477AD2                 lea     eax, \[ecx+eax\*2\]**

**00477AD5                 shl     eax, 4**

**00477AD8                 add     eax, ecx**

**00477ADA                 shl     eax, 4**

**00477ADD                 add     esi, eax**

**00477ADF                 add     esi, 10Ch**

**00477AE5                 push    esi  //此buffer既为进程表中不同进程对应的数据地址**

**00477AE6                 mov     eax, \[ebp+hWnd\]**

**00477AE9                 push    eax             ; hWnd**

**00477AEA                 call    GetWindowTextA  //获得枚举的窗口的标题并保存到进程表中对应的进程数据中**

** **

**00477AEF                 mov     byte ptr \[ebx+20Bh\], 0**

**00477AF6                 jmp     short loc\_477B07获得后跳出循环 利用枚举到的下一个窗口再次执行此函数**

** **

**如果进程ID不相等则继续循环**

**00477AF8                 inc     eax**

**00477AF9                 add     ebx, 310h  0x310为结构体大小**

**00477AFF loc\_477AFF:                           **

**00477AFF                 cmp     eax, \[edi+104h\] //检查比较的次数 是否大于进程表中 的进程数**

**00477B05                 jl      short loc\_477ABB**

** **

**在EnumWindows函数执行完成返回后，OD会调用InvalidateRect函数，使显示进程的窗口重绘;**

**004782F8                 push    0               ; bErase**

**004782FA                 push    0               ; lpRect**

**004782FC                 mov     edx, dword\_4ED3F8**

**00478302                 push    edx             ; hWnd**

**00478303                 call    InvalidateRect**

** **

**OD会对进程表中的 ID号，把相对应的索引数据进行从小到大的排序..**

**004AC501                 jz      short loc\_4AC51C**

**004AC503                 mov     edx, \[ebp+fcmp\]**

**004AC506                 mov     ecx, \[ebp+nelem\]**

**004AC509                 push    ecx //第一个参数为进程表中的数据个数**

**004AC50A                 mov     dword\_50A5F8, edx**

**004AC510                 mov     eax, \[ebp+base\] //第二个参数为进程表中索引数据的首地址**

**004AC513                 push    eax**

**004AC514                 call    sub\_4AC310**

**最终函数会调用到进程表结构体中偏移0x120位置保存的函数地址;**

** **

**当从进程窗口列表框中选择要附加的进程并点击附加按钮后，OD会记录其序号，并通过序号计算出此进程在 进程表中的 偏移位置，通过偏移位置得到进程ID**

** **

**004784A5                 mov     eax, dword\_4ED508//得到要附加进程在列表框中的位置**

**004784AA                 test    eax, eax**

**004784AC                 jl      loc\_47867B//如果进程号小于0则直接返回；**

**004784B2                 cmp     eax, dword\_4ED500/比较序号是否大于进程总数**

**004784B8                 jge     loc\_47867B  //大于也直接返回**

**004784BE                 mov     edx, dword\_4ED52C**

**004784C4                 mov     esi, \[edx+eax\*4\]**

**004784C7                 imul    esi, dword\_4ED510**

**004784CE                 add     esi, dword\_4ED518 //上面几步是计算得出附加的进程在进程表中存储的首地址**

**004784D4                 mov     eax, \[esi\]  //得到进程ID**

**004784D6                 cmp     eax, dword\_4D5A70 //判断OD是否正在调试此程序**

**004784DC                 jnz     short loc\_4784F4**

** **

**如果此时OD正在调试此程序则会弹出一错误框提示 进程“xxxx”是你正在调试的程序……**

**并直接返回。**

** **

**004784DE                 add     esi, 0Ch**

**004784E1                 push    esi             ; arglist**

**004784E2                 push    offset asc\_4C2122 ; "?**

**004784E7                 call    \_Error**

**004784EC                 add     esp, 8**

**004784EF                 jmp     loc\_47867B//直接返回..**

** **

**接着OD会申请一定的空间并初始化一些表，如：dll句柄表，线程表，统计表，等等…**

** **

**004784F4 loc\_4784F4:                           **

**004784F4                 push    1**

**004784F6                 call    sub\_4758A4**

**004784FB                 pop     ecx**

**004784FC                 test    eax, eax**

**004784FE                 jnz     loc\_47867B**

**00478504                 call    sub\_47540C //此函数用于申请空间并初始化表**

**00478509                 test    eax, eax //判断是否初始化成功。**

**0047850B                 jz      short loc\_47851D**

**0047850D                 push    offset aIFUC    ; "无法分配足够内存"**

**00478512                 call    \_Error//如果不成功则会报告内存内存不足…并直接返回**

**00478517                 pop     ecx**

**00478518                 jmp     loc\_47867B**

** **

**在0046b258这个函数中OD会根据用户设置的导入库保存在ollydbg.ini文件中的\[Import libraries\]项解析调试程序中的库函数;**

**下面就是处理的一个循环过程**

** **

**0046B268 loc\_46B268:                          **

**0046B268                 push    ebx**

**0046B269                 lea     eax, \[edi+4F8h\]**

**0046B26F                 push    eax             ; format**

**0046B270                 lea     edx, \[esp+318h+buffer\]**

**0046B277                 push    edx             ; buffer**

**0046B278                 call    \_sprintf**

**0046B27D                 add     esp, 0Ch**

**0046B280                 push    offset FileName ; lpFileName**

**0046B285                 push    104h            ; nSize**

**0046B28A                 lea     ecx, \[esp+318h+path\]**

**0046B28E                 push    ecx             ; lpReturnedString**

**0046B28F                 lea     eax, \[edi+4\]**

**0046B292                 push    eax             ; lpDefault**

**0046B293                 lea     edx, \[esp+320h+buffer\]**

**0046B29A                 push    edx             ; lpKeyName**

**0046B29B                 lea     ecx, \[edi+503h\]**

**0046B2A1                 push    ecx             ; lpAppName**

**0046B2A2                 call    GetPrivateProfileStringA  //得到ollydbg.ini 文件中\[Import libraries\]项中的路径**

**0046B2A7                 cmp     \[esp+310h+path\], 0**

**0046B2AB                 jz      short loc\_46B2E6**

**0046B2AD                 mov     eax, hCursor**

**0046B2B2                 push    eax             ; hCursor**

**0046B2B3                 call    SetCursor**

**0046B2B8                 mov     esi, eax**

**0046B2BA                 xor     eax, eax**

**0046B2BC                 mov     dword\_4EAE50, eax**

**0046B2C1                 push    0               ; int**

**0046B2C3                 lea     edx, \[esp+314h+arglist\]**

**0046B2CA                 push    edx             ; arglist**

**0046B2CB                 lea     ecx, \[esp+318h+path\]**

**0046B2CF                 push    ecx             ; path**

**0046B2D0                 call    sub\_469818//此函数里面主要是负责解析的函数**

**0046B2D5                 add     esp, 0Ch**

**0046B2D8                 call    sub\_46718C**

**0046B2DD                 cmp     dword\_4EAE50, 0**

**0046B2E4                 jnz     short loc\_46B2F3**

**0046B2E6**

**0046B2E6 loc\_46B2E6:     **

**0046B2E6                 inc     ebx**

**0046B2E7                 cmp     ebx, 0C8h**

**0046B2ED                 jl      loc\_46B268**

** **

**等做完上面的工作后，OD才开始真正的附加 主要是通过DebugActiveProcess对程序附加**

**00478522                 mov     eax, \[esi\]**

**00478524                 push    eax             /要附加的进程ID**

**00478525                 call    DebugActiveProcess**

**0047852A                 test    eax, eax**

** **

**之后OD按一定格式设置窗口标题；**

**004785A5                 push    edx**

**004785A6                 push    offset byte\_4D5A7C**

**004785AB                 push    offset aOllyice ; "OllyICE"**

**004785B0                 push    offset aSSS\_0   ; "%s - %s%s"**

**004785B5                 lea     ecx, \[ebp+buffer\]**

**004785BB                 push    ecx             ; buffer**

**004785BC                 call    \_sprintf**

**004785C1                 add     esp, 14h**

**004785C4                 lea     eax, \[ebp+buffer\] ; int**

**004785CA                 push    eax             ; lpString**

**004785CB                 mov     edx, hWnd**

**004785D1                 push    edx             ; hWnd**

**004785D2                 call    SetWindowTextA**

**然后OD会对ollydbg.ini文件中的\[History\]，\[Arguments\]两项进行设置……下面只贴出部分代码**

** **

**00476F08                 lea     edx, \[ebx+1\]**

**00476F0B                 push    edx**

**00476F0C                 lea     ecx, \[edi+6DAh\]**

**00476F12                 push    ecx             ; format**

**00476F13                 lea     eax, \[ebp+buffer\]**

**00476F19                 push    eax             ; buffer**

**00476F1A                 call    \_sprintf**

**00476F1F                 mov     edx, ebx**

**00476F21                 add     esp, 0Ch**

**00476F24                 shl     edx, 6**

**00476F27                 lea     ecx, \[ebp+var\_518\]**

**00476F2D                 add     edx, ebx**

**00476F2F                 push    offset FileName ; lpFileName**

**00476F34                 shl     edx, 2**

**00476F37                 lea     eax, \[ebp+buffer\]**

**00476F3D                 add     edx, ecx**

**00476F3F                 push    edx             ; lpString**

**00476F40                 lea     edx, \[edi+6E9h\]**

**00476F46                 push    eax             ; lpKeyName**

**00476F47                 push    edx             ; lpAppName**

**00476F48                 call    WritePrivateProfileStringA**

** **

**接着OD设置程序状态，并退出Dialog对话框…**

** **

**0047860E                 push    0               ; name**

**00478610                 push    offset byte\_4D5A7C ; int**

**00478615                 call    sub\_409370**

**0047861A                 add     esp, 8**

**0047861D                 push    3  //设置状态为运行**

**0047861F                 call    sub\_431978**

**00478624                 pop     ecx**

**00478625                 push    0               ; nResult**

**00478627                 push    ebx             ; hDlg**

**00478628                 call    EndDialog //结束附加窗口**

**0047862D                 jmp     short loc\_47867B**

** **

**DebugActiveProcess附加程序后，系统会为进程中的每一个创建线程，向调试器发送CREATE\_THREAD\_DEBUG\_EVENT调试事件，会为进程中的每个动态加载DLL向调试器发送LOAD\_DLL\_DEBUG\_EVENT调试事件..  OD通过WaitForDebugEvent函数获得这些事件，做相应处理，并调用ContinueDebugEvent使程序继续执行…..当这些都做完后，系统恢复进程中的所有线程，并且在第一个线程恢复的时候会执行 一个 断点指令，最后会调用Ntdll.dll中的DbgBreakPoint函数 而根据跟踪得知DbgBreakPoint中的实现 就是一个int3指令;**

** **

**dwDebugEventCode事件处理表：**

**0042EBF7                 mov     edx, DebugEvent.dwDebugEventCode**

**0042EBFD                 cmp     edx, 9          ; switch 10 cases**

**0042EC00                 ja      loc\_4313F4      ; default**

**0042EC00                                         ; jumptable 0042EC06 case 0**

**0042EC06                 jmp     ds:off\_42EC0D\[edx\*4\] ; switch jump**

**0042EC06 ; ---------------------------------------------------------------------------**

**0042EC0D off\_42EC0D      dd offset loc\_4313F4    ; DATA XREF: sub\_42EBD0+36r**

**0042EC0D                 dd offset loc\_42EC35    ; jump table for switch **

**0042EC0D                 dd offset loc\_430CFF**

**0042EC0D                 dd offset loc\_430DD7**

**0042EC0D                 dd offset loc\_430F3F**

**0042EC0D                 dd offset loc\_431037**

**0042EC0D                 dd offset loc\_43112D**

**0042EC0D                 dd offset loc\_4311B7**

**0042EC0D                 dd offset loc\_431276**

**0042EC0D                 dd offset loc\_4313C7**

** **

**DbgBreakPoint的实现**

** **

**7C92120E >  CC              int3     **

**7C92120F    C3              retn**

** **

**因此当程序执行到此时，会引起一个EXCEPTION\_DEBUG\_EVENT事件，OD通过WaitForDebugEvent函数会获得此调试事件…OD在获得EXCEPTION\_DEBUG\_EVENT事件后，之后并没有调用ContinueDebugEvent使程序执行。因此OD会停到DbgBreakPoint处，也就是EIP会指在retn处。**

转载于:https://www.cnblogs.com/kuangke/p/5363180.html