michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * Given a PID, this program attempts to inject a DLL into the process
michael@0:  * with that PID. The DLL it attempts to inject, "crashinjectdll.dll",
michael@0:  * must exist alongside this exe. The DLL will then crash the process.
michael@0:  */
michael@0: #include <stdio.h>
michael@0: #include <stdlib.h>
michael@0: #include <string.h>
michael@0: #include <windows.h>
michael@0: 
michael@0: int main(int argc, char** argv)
michael@0: {
michael@0:   if (argc != 2) {
michael@0:     fprintf(stderr, "Usage: crashinject <PID>\n");
michael@0:     return 1;
michael@0:   }
michael@0: 
michael@0:   int pid = atoi(argv[1]);
michael@0:   if (pid <= 0) {
michael@0:     fprintf(stderr, "Usage: crashinject <PID>\n");
michael@0:     return 1;
michael@0:   }
michael@0: 
michael@0:   // find our DLL to inject
michael@0:   wchar_t filename[_MAX_PATH];
michael@0:   if (GetModuleFileNameW(nullptr, filename,
michael@0:                          sizeof(filename) / sizeof(wchar_t)) == 0)
michael@0:     return 1;
michael@0: 
michael@0:   wchar_t* slash = wcsrchr(filename, L'\\');
michael@0:   if (slash == nullptr)
michael@0:     return 1;
michael@0: 
michael@0:   slash++;
michael@0:   wcscpy(slash, L"crashinjectdll.dll");
michael@0: 
michael@0:   // now find our target process
michael@0:   HANDLE targetProc = OpenProcess(PROCESS_VM_OPERATION | PROCESS_VM_WRITE | PROCESS_CREATE_THREAD | PROCESS_QUERY_INFORMATION,
michael@0:                                   FALSE,
michael@0:                                   pid);
michael@0:   if (targetProc == nullptr) {
michael@0:     fprintf(stderr, "Error %d opening target process\n", GetLastError());
michael@0:     return 1;
michael@0:   }
michael@0: 
michael@0:   /*
michael@0:    * This is sort of insane, but we're implementing a technique described here:
michael@0:    * http://www.codeproject.com/KB/threads/winspy.aspx#section_2
michael@0:    *
michael@0:    * The gist is to use CreateRemoteThread to create a thread in the other
michael@0:    * process, but cheat and make the thread function kernel32!LoadLibrary,
michael@0:    * so that the only remote data we have to pass to the other process
michael@0:    * is the path to the library we want to load. The library we're loading
michael@0:    * will then do its dirty work inside the other process.
michael@0:    */
michael@0:   HMODULE hKernel32 = GetModuleHandleW(L"Kernel32");
michael@0:   // allocate some memory to hold the path in the remote process
michael@0:   void*   pLibRemote = VirtualAllocEx(targetProc, nullptr, sizeof(filename),
michael@0:                                       MEM_COMMIT, PAGE_READWRITE);
michael@0:   if (pLibRemote == nullptr) {
michael@0:     fprintf(stderr, "Error %d in VirtualAllocEx\n", GetLastError());
michael@0:     CloseHandle(targetProc);
michael@0:     return 1;
michael@0:   }
michael@0: 
michael@0:   if (!WriteProcessMemory(targetProc, pLibRemote, (void*)filename,
michael@0:                           sizeof(filename), nullptr)) {
michael@0:     fprintf(stderr, "Error %d in WriteProcessMemory\n", GetLastError());
michael@0:     VirtualFreeEx(targetProc, pLibRemote, sizeof(filename), MEM_RELEASE);
michael@0:     CloseHandle(targetProc);
michael@0:     return 1;
michael@0:   }
michael@0:   // Now create a thread in the target process that will load our DLL
michael@0:   HANDLE hThread = CreateRemoteThread(
michael@0:                      targetProc, nullptr, 0,
michael@0:                      (LPTHREAD_START_ROUTINE)GetProcAddress(hKernel32,
michael@0:                                                             "LoadLibraryW"),
michael@0:                      pLibRemote, 0, nullptr);
michael@0:   if (hThread == nullptr) {
michael@0:     fprintf(stderr, "Error %d in CreateRemoteThread\n", GetLastError());
michael@0:     VirtualFreeEx(targetProc, pLibRemote, sizeof(filename), MEM_RELEASE);
michael@0:     CloseHandle(targetProc);
michael@0:     return 1;
michael@0:   }
michael@0:   WaitForSingleObject(hThread, INFINITE);
michael@0:   // Cleanup, not that it's going to matter at this point
michael@0:   CloseHandle(hThread);
michael@0:   VirtualFreeEx(targetProc, pLibRemote, sizeof(filename), MEM_RELEASE);
michael@0:   CloseHandle(targetProc);
michael@0: 
michael@0:   return 0;
michael@0: }