DebugPort 调用过程

DebugPort调用过程学习各种外挂制作技术，马上去百度搜索"魔鬼作坊"点击第一个站进入、快速成为做挂达人。

1一个程序被ring3调试器调试时，有很多的调试特征可以检测，本论坛也有专门的帖子详细论述，但有个非常根本的标志ring3也是可以检测的比较少人提及，那就是_EPROCESS.DebugPort。

DebugPort对于ring3调试器来说非常重要，没有它正常的ring3调试是无法进行的。

当然要检测这个标志的前提是程序能够读取ring0内存，在XP 以上的系统有个非常简单的方法就是使用ZwSystemDebugControl的SysDbgReadVirtualMemory方法，我们也可以mapphysicalmemory来操作。

检测DebugPort之前首先要得到进程的eprocess地址，这可以通过ZwQuerySystemInformation的SystemHandleInformation方法得到，也可以直接搜索ring0内存的eprocess结构。

对于ring3直接检测DebugPort，我们可以通过禁止该进程访问ring0内存来对付，但是目标一旦使用驱动来检测，那么就非常麻烦了。

下面介绍一种隐藏_EPROCESS.DebugPort的方法，这种方法的基本思路是，将一个正常被调试进程的DebugPort置零后，修正所有受影响的函数，使我们的调试器能够正常进行。

这些函数如下：PspCreateProcess、MmCreatePeb进程创建，设置DebugPortDbgkCreateThread发送线程或者进程创建的调试信息KiDispatchException、DbgkForwardException和DbgkpQueueMessage发送异常调试信息PspExitThread、DbgkExitThread和DbgkExitProcess发送线程退出、进程退出的调试信息DbgkMapViewOfSection和DbgkUnMapViewOfSection发送映像装载卸载调试信息DbgkpSetProcessDebugObject和DbgkpMarkProcessPeb当调试器附加进程时设置DebugPort这类函数非常多的，如果都HOOK处理的话，那太恐怖了，这里使用一个非常简单的办法：偷龙转凤。

我们看系统访问DebugPort的代码都是这样的（XP）8b89bc000000mov ecx,dword ptr[ecx+0BCh]//0BCh就是DebugPort的偏移我们可以把DebugPort转移到_EPROCESS的另外一个地方，比如我使用+0x070CreateTime，它是纪录进程创建时间的，进程创建之后，在进程退出前系统不会对它进行任何修改，而且我们修改后对系统或进程没有任何影响。

这样我们可以把上面的代码改成这样8b8970000000mov ecx,dword ptr[ecx+070h]//指向CreateTime，实际的DebugPort已经被移到这里只需要修改一个字节，非常简单。

当然这种方法最麻烦的地方就是定位引用到DebugPort的函数（本人仅仅针对不同的XP系统制作特征码都累到吐血），这些函数都是不导出的，如果是特定系统，最简单的方法就是WinDbg->uf***直接找地址硬编码，只需要几分钟时间。

BOOLEAN InitHackAddress()2{3_SEH_TRY4{5g_KernelBase=GetKernelBaseAndSize(&g_KernelSize);6g_HackPspCreateProcess= SearchHackPspCreateProcess(&g_NopPspCreateProcess.Address);7g_HackKiDispatchException=SearchKiDispatchException(g_KernelBase,g_KernelSize);8g_HackDbgkpQueueMessage= SearchDbgkpQueueMessage(g_KernelBase,g_KernelSize);9g_HackDbgkCreateThread= SearchDbgkCreateThread(g_KernelBase,g_KernelSize);10SearchDbgkNotifyRoutine(g_KernelBase,g_KernelSize);11g_HackPspExitThread=SearchPspExitThread();12g_HackMmCreatePeb=SearchMmCreatePeb(g_HackPspCreateProcess); 13SearchDbgkpSetProcessDebugObject(g_KernelBase,g_KernelSize);14if(g_HackDbgkpSetProcessDebugObject[3])15g_HackDbgkpMarkProcessPeb= SearchDbgkpMarkProcessPeb(g_HackDbgkpSetProcessDebugObject[3]);1617if(g_NopPspCreateProcess.Address!=0){18RtlFillMemory(g_NopPspCreateProcess.NopCode,sizeof(g_NopPspCreateProcess. NopCode),0x90);19g_NopPspCreateProcess.Size=9;20RtlCopyMemory(g_NopPspCreateProcess.OrigCode,(PVOID)g_NopPspCreateProce ss.Address,g_NopPspCreateProcess.Size);21}22if(g_NopDbgkForwardException.Address!=0){23RtlFillMemory(g_NopDbgkForwardException.NopCode,sizeof(g_NopDbgkForwardE xception.NopCode),0x90);24RtlCopyMemory(g_NopDbgkForwardException.OrigCode,(PVOID)g_NopDbgkForwa rdException.Address,g_NopDbgkForwardException.Size);25}26if(g_NopDbgkExitThread.Address!=0){27RtlFillMemory(g_NopDbgkExitThread.NopCode,sizeof(g_NopDbgkExitThread.NopC ode),0x90);28RtlCopyMemory(g_NopDbgkExitThread.OrigCode,(PVOID)g_NopDbgkExitThread.A ddress,g_NopDbgkExitThread.Size);29}30if(g_NopDbgkExitProcess.Address!=0){31RtlFillMemory(g_NopDbgkExitProcess.NopCode,sizeof(g_NopDbgkExitProcess.Nop Code),0x90);32RtlCopyMemory(g_NopDbgkExitProcess.OrigCode,(PVOID)g_NopDbgkExitProcess. Address,g_NopDbgkExitProcess.Size);33}34if(g_NopDbgkMapViewOfSection.Address!=0){35RtlFillMemory(g_NopDbgkMapViewOfSection.NopCode,sizeof(g_NopDbgkMapView OfSection.NopCode),0x90);36RtlCopyMemory(g_NopDbgkMapViewOfSection.OrigCode,(PVOID)g_NopDbgkMapV iewOfSection.Address,g_NopDbgkMapViewOfSection.Size);37}38if(g_NopDbgkUnMapViewOfSection.Address!=0){39RtlFillMemory(g_NopDbgkUnMapViewOfSection.NopCode,sizeof(g_NopDbgkUnMa pViewOfSection.NopCode),0x90);40RtlCopyMemory(g_NopDbgkUnMapViewOfSection.OrigCode,(PVOID)g_NopDbgkUn MapViewOfSection.Address,g_NopDbgkUnMapViewOfSection.Size);41}424344}45_SEH_HANDLER46{47DbgPrint("InitHackAddress Exception!\n");48}49return(g_HackPspCreateProcess!=0&&50g_HackKiDispatchException!=0&&51g_HackDbgkForwardException!=0&&52g_HackDbgkpQueueMessage!=0&&53g_NopPspCreateProcess.Address!=0&&54g_NopDbgkForwardException.Address!=0&&55g_HackDbgkCreateThread!=0&&56g_HackDbgkExitThread!=0&&57g_NopDbgkExitThread.Address!=0&&58g_HackDbgkExitProcess!=0&&59g_NopDbgkExitProcess.Address!=0&&60g_HackDbgkMapViewOfSection!=0&&61g_NopDbgkMapViewOfSection.Address!=0&&62g_HackDbgkUnMapViewOfSection!=0&&63g_NopDbgkUnMapViewOfSection.Address!=0&&64g_HackPspExitThread!=0&&65g_HackMmCreatePeb!=0&&66g_HackDbgkpSetProcessDebugObject[0]!=0&&67g_HackDbgkpSetProcessDebugObject[1]!=0&&68g_HackDbgkpSetProcessDebugObject[2]!=0&&69g_HackDbgkpSetProcessDebugObject[3]!=0&&70g_HackDbgkpMarkProcessPeb!=0);71}//修改已经运行进程的DebugPort位置72BOOLEAN ChangeProcessDebugPort(BOOLEAN Hide)73{74ULONG eProcess=(ULONG)PsInitialSystemProcess;75PLIST_ENTRY pListHead,pListWalk;76ULONG DebugObject;77if(!g_bIsAddressStartup){78return FALSE;79}80pListHead=(PLIST_ENTRY)(eProcess+ACTIVE_LINKS_OFFSET);81pListWalk=pListHead;82_SEH_TRY83{84do{85if(pListWalk==NULL||eProcess==0)86break;87eProcess=((ULONG)pListWalk-ACTIVE_LINKS_OFFSET);88if(Hide){89DebugObject=*(ULONG*)(eProcess+DEBUG_PORT_OFFSET); 90*(ULONG*)(eProcess+CREATE_TIME_OFFSET)=DebugObject; 91*(ULONG*)(eProcess+DEBUG_PORT_OFFSET)=0;92}else{93DebugObject=*(ULONG*)(eProcess+CREATE_TIME_OFFSET); 94*(ULONG*)(eProcess+DEBUG_PORT_OFFSET)=DebugObject; 95}96pListWalk=pListWalk->Flink;97}while(pListWalk!=pListHead);98}99_SEH_HANDLER100{101DbgPrint("ChangeProcessDebugPortexception!\n");102}103104return TRUE;105}106代码:107BOOLEANModifyDebugFunction()108{109if(!g_bIsAddressStartup){110returnFALSE;111}112__asm{113cli114mov eax,cr0115and eax,not10000h116mov cr0,eax117}118*(ULONG*)g_HackPspCreateProcess=CREATE_TIME_OFFSET;119*(ULONG*)g_HackKiDispatchException=CREATE_TIME_OFFSET;120*(ULONG*)g_HackDbgkForwardException=CREATE_TIME_OFFSET;121*(ULONG*)g_HackDbgkpQueueMessage=CREATE_TIME_OFFSET;122*(ULONG*)g_HackDbgkCreateThread=CREATE_TIME_OFFSET;123*(ULONG*)g_HackDbgkExitThread=CREATE_TIME_OFFSET;124*(ULONG*)g_HackDbgkExitProcess=CREATE_TIME_OFFSET;125*(ULONG*)g_HackDbgkMapViewOfSection=CREATE_TIME_OFFSET;126*(ULONG*)g_HackDbgkUnMapViewOfSection=CREATE_TIME_OFFSET;127*(ULONG*)g_HackPspExitThread=CREATE_TIME_OFFSET;128*(ULONG*)g_HackDbgkpMarkProcessPeb=CREATE_TIME_OFFSET;129*(ULONG*)g_HackMmCreatePeb=CREATE_TIME_OFFSET;130*(ULONG*)g_HackDbgkpSetProcessDebugObject[0]= CREATE_TIME_OFFSET;131*(ULONG*)g_HackDbgkpSetProcessDebugObject[1]= CREATE_TIME_OFFSET;132*(ULONG*)g_HackDbgkpSetProcessDebugObject[2]= CREATE_TIME_OFFSET;133*(ULONG*)g_HackDbgkpSetProcessDebugObject[3]= CREATE_TIME_OFFSET;134135RtlCopyMemory((PVOID)g_NopPspCreateProcess.Address,g_NopPspCreateProces s.NopCode,g_NopPspCreateProcess.Size);136RtlCopyMemory((PVOID)g_NopDbgkForwardException.Address,g_NopDbgkForward Exception.NopCode,g_NopDbgkForwardException.Size);137RtlCopyMemory((PVOID)g_NopDbgkExitThread.Address,g_NopDbgkExitThread.No pCode,g_NopDbgkExitThread.Size);138RtlCopyMemory((PVOID)g_NopDbgkExitProcess.Address,g_NopDbgkExitProcess.N opCode,g_NopDbgkExitProcess.Size);139RtlCopyMemory((PVOID)g_NopDbgkMapViewOfSection.Address,g_NopDbgkMapVi ewOfSection.NopCode,g_NopDbgkMapViewOfSection.Size);140RtlCopyMemory((PVOID)g_NopDbgkUnMapViewOfSection.Address,g_NopDbgkUn MapViewOfSection.NopCode,g_NopDbgkUnMapViewOfSection.Size);141__asm{142mov eax,cr0143or eax,10000h144mov cr0,eax145sti146}147return TRUE;148}149BOOLEAN WriteBackDebugFunction()150{151if(!g_bIsAddressStartup){152return FALSE;153}154__asm{155cli156mov eax,cr0157and eax,not10000h158mov cr0,eax159}160*(ULONG*)g_HackPspCreateProcess=DEBUG_PORT_OFFSET;161*(ULONG*)g_HackKiDispatchException=DEBUG_PORT_OFFSET;162*(ULONG*)g_HackDbgkForwardException=DEBUG_PORT_OFFSET;163*(ULONG*)g_HackDbgkpQueueMessage=DEBUG_PORT_OFFSET;164*(ULONG*)g_HackDbgkCreateThread=DEBUG_PORT_OFFSET;165*(ULONG*)g_HackDbgkExitThread=DEBUG_PORT_OFFSET;166*(ULONG*)g_HackDbgkExitProcess=DEBUG_PORT_OFFSET;167*(ULONG*)g_HackDbgkMapViewOfSection=DEBUG_PORT_OFFSET;168*(ULONG*)g_HackDbgkUnMapViewOfSection=DEBUG_PORT_OFFSET;169*(ULONG*)g_HackPspExitThread=DEBUG_PORT_OFFSET;170*(ULONG*)g_HackDbgkpMarkProcessPeb=DEBUG_PORT_OFFSET;171*(ULONG*)g_HackMmCreatePeb=DEBUG_PORT_OFFSET;172*(ULONG*)g_HackDbgkpSetProcessDebugObject[0]= DEBUG_PORT_OFFSET;173*(ULONG*)g_HackDbgkpSetProcessDebugObject[1]= DEBUG_PORT_OFFSET;174*(ULONG*)g_HackDbgkpSetProcessDebugObject[2]= DEBUG_PORT_OFFSET;175*(ULONG*)g_HackDbgkpSetProcessDebugObject[3]= DEBUG_PORT_OFFSET;176RtlCopyMemory((PVOID)g_NopPspCreateProcess.Address,g_NopPspCreateProces s.OrigCode,g_NopPspCreateProcess.Size);177RtlCopyMemory((PVOID)g_NopDbgkForwardException.Address,g_NopDbgkForward Exception.OrigCode,g_NopDbgkForwardException.Size);178RtlCopyMemory((PVOID)g_NopDbgkExitThread.Address,g_NopDbgkExitThread.Ori gCode,g_NopDbgkExitThread.Size);179RtlCopyMemory((PVOID)g_NopDbgkExitProcess.Address,g_NopDbgkExitProcess.O rigCode,g_NopDbgkExitProcess.Size);180RtlCopyMemory((PVOID)g_NopDbgkMapViewOfSection.Address,g_NopDbgkMapVi ewOfSection.OrigCode,g_NopDbgkMapViewOfSection.Size);181RtlCopyMemory((PVOID)g_NopDbgkUnMapViewOfSection.Address,g_NopDbgkUn MapViewOfSection.OrigCode,g_NopDbgkUnMapViewOfSection.Size);182__asm{183mov eax,cr0184or eax,10000h185mov cr0,eax186sti187}188return TRUE;189}我想再嗦一下，上面代码大家看到很多函数有个NOPCode，这个实际上是对付线程PS_C ROSS_THREAD_FLAGS_HIDEFROMDBG的，NOP掉相关地方后，就算线程被设置为T hreadHideFromDebugger也无法阻挡调试器接收调试信息。