Getting Base Address not working - c++

I need the base Address of the exe "tibia.exe". This is what I got so far but it doesn't work. It always returns 0.
What's wrong?
DWORD MainWindow::getBaseAddress(DWORD dwProcessIdentifier)
{
TCHAR lpszModuleName[] = {'t','i','b','i','a','.','e','x','e','\0'}; //tibia.exe
HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE,
dwProcessIdentifier);
DWORD dwModuleBaseAddress = 0;
if(hSnapshot != INVALID_HANDLE_VALUE)
{
MODULEENTRY32 ModuleEntry32;
ModuleEntry32.dwSize = sizeof(MODULEENTRY32);
if(Module32First(hSnapshot, &ModuleEntry32))
{
do
{
if( wcscmp(ModuleEntry32.szModule, lpszModuleName) == 0)
{
dwModuleBaseAddress = (DWORD)ModuleEntry32.modBaseAddr;
break;
}
}
while(Module32Next(hSnapshot, &ModuleEntry32));
}
CloseHandle(hSnapshot);
}
return dwModuleBaseAddress;
}
//Call it here
tibiaWindow = FindWindow( L"TibiaClient", NULL);
DWORD PID;
GetWindowThreadProcessId( tibiaWindow, &PID );
DWORD baseAddress = getBaseAddress( PID );
if( baseAddress == 0 )
return false ;

Perhaps it's just because I was using them before ToolHelp32 was available (at least on the NT-based operating systems), but I tend to use the PSAPI functions for this kind of task. Using them, the code would look like this:
#include <windows.h>
#include <string>
#include <psapi.h>
#include <iostream>
int main(int argc, char **argv) {
HANDLE process = GetCurrentProcess();
if (argc != 1)
process = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, false, atoi(argv[1]));
HMODULE handles[2048];
DWORD needed;
EnumProcessModules(process, handles, sizeof(handles), &needed);
for (int i = 0; i < needed / sizeof(handles[0]); i++) {
MODULEINFO info;
char name[1024];
GetModuleBaseName(process, handles[i], name, sizeof(name));
if (std::string(name).find(".exe") != std::string::npos) {
GetModuleInformation(process, handles[i], &info, sizeof(info));
std::cout << name << ": " << info.lpBaseOfDll << "\n";
break;
}
}
}
As it stands right now, this will let you enter a process ID on the command line, and show the load address of the first module it finds in that process with a name that includes ".exe". If you don't specify a process ID, it'll search through its own process (demos how the functions work, but otherwise pretty much useless).
Using either ToolHelp32 or PSAPI, you end up with a similar limitation: you need to compile this into a 64-bit executable for it to be able to "see" other 64-bit processes (i.e., when compiled as 32-bit code, they see only other 32-bit processes).
There are also some processes (e.g., CSRSS.exe) that neither will be able to open/enumerate successfully. As far as I know, the same processes will succeed/fail with PSAPI vs. ToolHelp32.
PSAPI does have one bit of clumsiness compared to ToolHelp32: dealing (well) with processes that have lots of modules is clumsy (at best). You call EnumProcessModules, and if you haven't given room for enough modules, the "Needed" parameter will be set to the space needed for the number of modules it contains. There's a race condition though: between the time that returns and the time you call EnumProcessModules again, the process could have loaded more DLLs, so that second call could fail the same way.
For the moment, I've just assumed that no process will use more than 2048 modules. To be really correct, you should have a while loop (or maybe a do/while loop) that starts with zero space, calls EnumProcessModules to find out how much space is needed, allocate that (perhaps with a little extra in case it loads more DLLs) and repeat until it succeeds.

Related

Ejecting dll by calling CreateRemoteThread : crash

I am trying to make for myself a tool for extracting/releasing dlls from processes. I have already experienced with LoadLibrary and injecting but this time the logic doesn't seem to apply.
This is my code:
HMODULE findModuleOffset(HANDLE proc, char *mod_name) {
//Finds module address in specified process. 0 if not found
HMODULE hMods[2048];
DWORD modules_byte_size;
if (EnumProcessModules(proc, hMods, sizeof(hMods), &modules_byte_size))
{
for (unsigned long i = 0; i < (modules_byte_size / sizeof(HMODULE)); i++) {
CHAR module_name[MAX_PATH];
// Get the full path to the module's file.
if (GetModuleFileNameExA(proc, hMods[i], module_name, sizeof(module_name))) {
if (strcmp(strrchr(module_name,'.')+1,"exe")!=0 && compareExeName(module_name, mod_name)) {
return hMods[i];
}
}
}
}
return 0;
}
bool compareExeName(char *path, char *partial_name) {
//This will substract the filename from path and compare it with partial_name
char *lastSlash = strrchr(path, '\\') + 1;
if (lastSlash != NULL && strstr(lastSlash, partial_name) == lastSlash) return 1;
return 0;
}
void unload_all_dll(char *dll_name) {
DWORD process_ids[2048];
DWORD process_byte_size; //size of filled process_ids in BYTES (after the call)
DWORD process_count; //count of all elements in process_ids
HMODULE ext_dll_module;
HANDLE opened_process;
HANDLE Hthread;
DWORD thread_exit_code = 1;
CHAR exe_path[1024];
if (EnumProcesses(process_ids, sizeof(process_ids), &process_byte_size)) {
process_count = process_byte_size / sizeof(DWORD);
for (int i = 0; i < process_count; i++) {
thread_exit_code = 0;
if ((opened_process = OpenProcess(PROCESS_ALL_ACCESS, false, process_ids[i])) == NULL) continue;
GetModuleFileNameExA(opened_process, 0, exe_path, MAX_PATH);
if ((ext_dll_module = findModuleOffset(opened_process, dll_name)) != 0) {
while (thread_exit_code == 0) {
if ((Hthread = CreateRemoteThread(opened_process, NULL, 0, (LPTHREAD_START_ROUTINE)GetProcAddress(GetModuleHandleA("kernel32.dll"), "FreeLibrary"), (void*)ext_dll_module, 0, NULL)) == NULL) {
cout<<"Process closed meanwhile or dll unloaded";
break; //process has closed meanwhile
}
while (WaitForSingleObject(Hthread, 1000) == WAIT_TIMEOUT);
GetExitCodeThread(Hthread, &thread_exit_code);
}
cout << "Dll unloaded from " << exe_path << endl;
}
}
}
}
Warning:some variables names might be confusing(I am in hurry)
But every time I try to eject a dll everything crashes(of course,only the apps that contained the specfied dll). I tested everything I could and everything seems fine: the module address returned by findModuleOffset is good(checked against the value given by process explorer). I have no ideea what the return value of createremotethread or thread_exit_code is because the app crashes(it contasins the dll to be ejected..so...). Can you help me?
(moving from the comments)
Given that there are threads in the target process that are running code from the dll being unloaded, they are going to crash immediately after the dll gets freed - after all, the very pages of code that the CPU is executing are being unmapped!
To avoid the problem, the running threads have to be notified in some way, so they can terminate before unloading the dll; Windows provides many IPC methods, one rarely used is particularly well-fitted for this case, namely mailslots.
When the dll is injected, the "master" thread that gets created will create a mailslot with a well-known name, and periodically check if there's any message for him. When you want to unload the dlls, instead of brutally injecting a thread that forcefully frees the dll, just ask to your "inside man": post a message to the mailslot asking it to terminate1.
The thread will see that there's a message in the mailslot, take care to possibly terminate the other threads that were started inside the target process (a shared atomic variable + WaitForSingleObject can be used) and, when the cleanup is finished, call FreeLibraryAndExitThread to suicide both the last thread and the dll.
Notes
A particularly interesting peculiarity of mailslots is that, if they are created multiple times with the same name, messages sent to such a name will be delivered to all them, so if, as it seems, you want to shut down all the injected dlls at the same time, this greatly simplifies the controlling program - there's not even need to enumerate the running processes.

EnumProcesses - weird behaviour

I have some weird behaviour while using WIndows API function EnumProcesses()
I have a function to determine wether a process with a certain name is already running which delivery different results wether I open the .executable manually (doubleclick) or open it via shell.
When I open it via shell it detects its running only 1 time (itself) and all is fine. When I open it using doubleclick on the .exe file however the function is returning true (already running) because the loop lists me the same process twice.
For the following code-snipped it is to mention that:
this->thisExecutableFile
contains argv[0] (initialised from running the program) to get the own process-name as you can see here:
int main(int argc, char* argv[])
{
ClientUpdate* update = ClientUpdate::getInstance();
update->setThisExecutableFile(argv[0]);
if (update->clientUpdateProcessIsRunning() == false) {
...
My goal is to find out if another instance of this process is already running and in this case exit it.
Here is my code:
bool ClientUpdate::clientUpdateProcessIsRunning()
{
bool retVal = false;
uint16_t processCount = 0;
unsigned long aProcesses[1024], cbNeeded, cProcesses;
if(!EnumProcesses(aProcesses, sizeof(aProcesses), &cbNeeded))
return false;
cProcesses = cbNeeded / sizeof(unsigned long);
for(unsigned int i = 0; i < cProcesses; i++) {
if (aProcesses[i] == 0) {
continue;
}
HANDLE hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, 0, aProcesses[i]);
wchar_t buffer[50];
GetModuleBaseNameW(hProcess, 0, buffer, 50);
CloseHandle(hProcess);
std::wstring tempBuffer(buffer);
std::string tempStringBuffer(tempBuffer.begin(), tempBuffer.end());
boost::filesystem::path p(this->thisExecutableFile);
if(_strcmpi(p.filename().string().c_str(), tempStringBuffer.c_str()) == 0) {
processCount++;
if(processCount > 1) {
retVal = true;
break;
}
}
}
return retVal;
}
I know that the base-path is different when using doubleclick on the file or calling it via shell. (shell produces only filename while doubleclick passes entire path + filename into argv[0]) but I fixed that issue using
boost::filesystem::path p(this->thisExecutableFile);
p.fileName()
Which returns the correct filename (without path) in both cases I checked using print.
I am pretty puzzled why EnumProcesses() returns me the same file twice when calling the file via doubleclick instead of shell. Its not spawning two processed and in taskmanager I dont see anything like this either.
Is this a bug or I need to know something about the method I couldnt find in docs?
Thanks to the hint by Richard Critten I was able to fix it. My method is much smaller now and easier. (Also probably also alot more performant then scanning entire process-stack.) :D
Here is the solution
bool ClientUpdate::clientUpdateProcessIsRunning()
{
HANDLE hMutex = CreateMutexA(NULL, TRUE, "client-updater-mtx");
DWORD dwErr = GetLastError();
return dwErr == ERROR_ALREADY_EXISTS;
}
Thanks!

Windows program entry point using EnumProcessModules returns unexpected value

I am running a simple app and trying to read a specific offset within it's memory using Window's PSAPI.
when I run my debugger, I get the real value of the memory address, and the relative one to my ".exe" entry point.
yet, when I run the following code, the base module I get as an entry point together with my offset yields a different address(it's wrong, and off by a few (hexa)demical points).
what might be the problem?
ReadMemory is a template for ReadProcessMemory
HWND WINDOW_HANDLE;
HANDLE PROC_HANDLE;
DWORD PROC_ID;
DWORD address;
SIZE_T bytesRead;
int InitReadMemory(const char* windowClass,const char* caption, DWORD addressOffset)
{
DWORD cbNeeded;
DWORD dwdResult;
HMODULE mainModule;
BOOL enumResult;
//Get the window handle
WINDOW_HANDLE = FindWindow(windowClass, NULL);
if(WINDOW_HANDLE == NULL)
{
//Window was not foud
return 10;
}
//Get the process ID
dwdResult = GetWindowThreadProcessId(WINDOW_HANDLE, &PROC_ID);
if(dwdResult==0)
{
//Getting Process ID failed
return 20;
}
//Open the process
PROC_HANDLE = OpenProcess(PROCESS_ALL_ACCESS, false, PROC_ID);
if(PROC_HANDLE==NULL)
{
//Process failed to open
return 30;
}
/*
*Get the Main Module-
*first entry in the returned HMODULE array from
*EnumProcessModules
*/
enumResult = EnumProcessModules(PROC_HANDLE, &mainModule, sizeof(HMODULE), &cbNeeded);
if(enumResult != 0)
{
//Failed enumerating process modules
return 40;
}
//offset the requested memory address from the application's base address
address = (DWORD)((UINT_PTR)mainModule + addressOffset);
#ifdef DEBUG
using namespace std;
char filenameBuffer[64]="";
string number;
stringstream stristream;
stristream << address;
stristream >> number;
cout << number << "\r\n" << endl;
GetModuleFileNameEx(PROC_HANDLE, mainModule , filenameBuffer, 256);
cout << (byte)ReadMemory<byte>() << "\r\n" << number << "\r\n" << filenameBuffer << endl;
system("PAUSE");
#endif
return 1;}
thank you in advance :)
P.S. I'm mostly just looking for pointers ...
bah dum tsss
Update:
apparently, checking for GetLastError value, EnumProcessModules prompts a 299 error code after it is done. and debugging shows that mainModule holds nothing... yet EnumProcessModules returns 0 as in "no errors".
yesterday, I managed to get it AND get GetModuleFileName to work propery(same code, only added GetLastError).
Apparently, my problem was that I was running the tests with the snippet
enumResult = EnumProcessModules(PROC_HANDLE, &mainModule, sizeof(HMODULE), &cbNeeded)
if(enumResult != 0)
{
//Failed enumerating process modules
return 40;
}
and a successful run of EnumProcessModules yields a nonzero result! (thus causing me some confusion and faulted my whole debugging process)
after I figured this detail out, I ran some old tests again and found out that my target process is 64 bit, while I was running a 32 bit application.
changed to 64bit and now it works like a charm

Can i block a program using ASM?

I am trying for a few days to block a cheat program for my game, i talked with several coders, and one said i can block it using ASM. The program hides very good, i cannot find it in memory, i cannot detect it scanning processes, so maybe this could be the solution? Can someone give me a example how can i detect and block a program with c++ and ASM?
This is my current method to detect and block cheats, using memory dumps:
void SystemProcessesScan()
{
HANDLE hProcessSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
if(hProcessSnap != INVALID_HANDLE_VALUE)
{
PROCESSENTRY32 pe32;
pe32.dwSize = sizeof(PROCESSENTRY32);
if(Process32First(hProcessSnap, &pe32))
{
do
{
HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, pe32.th32ProcessID);
if(hProcess != NULL)
{
if(ScanProcessMemory(hProcess))
{
ExitProcess(0);
}
}
}
while(Process32Next(hProcessSnap, &pe32));
}
}
CloseHandle(hProcessSnap);
}
bool ScanProcessMemory(HANDLE hProcess)
{
for(int i = 0; i < MAX_PROCESS_DUMP; i++)
{
char aTmpBuffer[MAX_DUMP_SIZE];
SIZE_T aBytesRead = 0;
ReadProcessMemory(hProcess, (LPCVOID)g_ProcessesDumps[i].m_aOffset, (LPVOID)aTmpBuffer, sizeof(aTmpBuffer), &aBytesRead);
if(memcmp(aTmpBuffer, g_ProcessesDumps[i].m_aMemDump, MAX_DUMP_SIZE) == 0)
{
return true;
break;
}
}
return false;
}
The cheat injects a DLL into your game and it sounds like it uses manual mapping to hide the DLL in memory.
The best solution to detect it is to find a sequence of bytes that are unique to this DLL. Pattern scan your own game processes, if the signature is found, close the game or whatever you want to do at that point.
Search for C++ internal pattern scanning or signature scanning, there are dozens of sources floating around that are uses regularly for this purpose.
Due to it being manually mapped, you must scan all committed memory regions rather than looping through the list of modules. Use VirtualQuery() in a while loop starting with address 0 until it fails.

Unloading an Injected DLL

I have a DLL I inject into other processes using SetWindowsHookEx. Inside the DLL I increment the module's reference counter by calling GetModuleHandleEx so I can control when the module is unloaded.
At this point the module reference count "should be" 2 from both of those API calls. When the calling process shuts down, it calls UnhookWindowsHookEx, decrementing the reference count to 1. The DLL has a thread that waits on a few things, one of them being the handle of the process that called SetWindowsHookEx. When the process goes away the DLL does some cleanup, terminates all threads, cleans up memory and handles and then calls FreeLibraryAndExitThread. This decrements the counter and the DLL gets unloaded.
Here's my problem. There are a few processes, especially those without a UI, where the DLL never gets unloaded. I'm pretty confident I have cleaned up everything. And I know for a fact that none of my threads are running.
First of all, if you have any troubleshooting tips to help uncover the cause, that would be helpful. Otherwise, I was thinking about using some API like NtQueryInformationProcess to get the module address and confirm the module handle count is in fact zero, then call CreateRemoteThread to inject a call to LdrUnloadDll to unload the module address from within the process. What are your thoughts to this approach? Does anyone have any example code? I'm having difficulty finding out how to get the module handle count.
Okay.. here goes.. There are many ways to get the module info from a process. The undocumented way and the "documented" way.
Results (documented):
Here is the "documented" way..
#include <windows.h>
#include <TlHelp32.h>
#include <iostream>
#include <sstream>
int strcompare(const char* One, const char* Two, bool CaseSensitive)
{
#if defined _WIN32 || defined _WIN64
return CaseSensitive ? strcmp(One, Two) : _stricmp(One, Two);
#else
return CaseSensitive ? strcmp(One, Two) : strcasecmp(One, Two);
#endif
}
PROCESSENTRY32 GetProcessInfo(const char* ProcessName)
{
void* hSnap = nullptr;
PROCESSENTRY32 Proc32 = {0};
if ((hSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)) == INVALID_HANDLE_VALUE)
return Proc32;
Proc32.dwSize = sizeof(PROCESSENTRY32);
while (Process32Next(hSnap, &Proc32))
{
if (!strcompare(ProcessName, Proc32.szExeFile, false))
{
CloseHandle(hSnap);
return Proc32;
}
}
CloseHandle(hSnap);
Proc32 = { 0 };
return Proc32;
}
MODULEENTRY32 GetModuleInfo(std::uint32_t ProcessID, const char* ModuleName)
{
void* hSnap = nullptr;
MODULEENTRY32 Mod32 = {0};
if ((hSnap = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, ProcessID)) == INVALID_HANDLE_VALUE)
return Mod32;
Mod32.dwSize = sizeof(MODULEENTRY32);
while (Module32Next(hSnap, &Mod32))
{
if (!strcompare(ModuleName, Mod32.szModule, false))
{
CloseHandle(hSnap);
return Mod32;
}
}
CloseHandle(hSnap);
Mod32 = {0};
return Mod32;
}
std::string ModuleInfoToString(MODULEENTRY32 Mod32)
{
auto to_hex_string = [](std::size_t val, std::ios_base &(*f)(std::ios_base&)) -> std::string
{
std::stringstream oss;
oss << std::hex << std::uppercase << val;
return oss.str();
};
std::string str;
str.append(" =======================================================\r\n");
str.append(" Module Name: ").append(Mod32.szModule).append("\r\n");
str.append(" =======================================================\r\n\r\n");
str.append(" Module Path: ").append(Mod32.szExePath).append("\r\n");
str.append(" Process ID: ").append(std::to_string(Mod32.th32ProcessID).c_str()).append("\r\n");
str.append(" Load Count (Global): ").append(std::to_string(static_cast<int>(Mod32.GlblcntUsage != 0xFFFF ? Mod32.GlblcntUsage : -1)).c_str()).append("\r\n");
str.append(" Load Count (Process): ").append(std::to_string(static_cast<int>(Mod32.ProccntUsage != 0xFFFF ? Mod32.ProccntUsage : -1)).c_str()).append("\r\n");
str.append(" Base Address: 0x").append(to_hex_string(reinterpret_cast<std::size_t>(Mod32.modBaseAddr), std::hex).c_str()).append("\r\n");
str.append(" Base Size: 0x").append(to_hex_string(Mod32.modBaseSize, std::hex).c_str()).append("\r\n\r\n");
str.append(" =======================================================\r\n");
return str;
}
int main()
{
PROCESSENTRY32 ProcessInfo = GetProcessInfo("notepad.exe");
MODULEENTRY32 ME = GetModuleInfo(ProcessInfo.th32ProcessID, "uxtheme.dll");
std::cout<<ModuleInfoToString(ME);
}
The problem with the undocumented API is that I've never figured out why the load counts are always "6" for dynamic modules and "-1" for static modules.. For this reason, I will not post it..
It is BEST NOT to use undocumented API if you want just the load count. The undocumented API's only advantage is that you can use it to "un-link/hide" a module within a process (like viruses do).. It will "unlink/hide" it.. NOT "unload" it. This means that at any time, you can "re-link" it back into the process's module list.
Since you only need the module-reference-count, I've only included "documented" API which does exactly that.
I found the cause of the problem and the solution. I honestly feel quite stupid for missing it and struggling with it for so long.
As I mentioned in the original problem, the processes that are problematic do not have a UI. Turns out they do have a message pump running. The problem is nothing is sending messages to these processes without a UI after we call UnhookWindowsHookEx that would trigger the unloading. (In fact, I believe MSDN does state that window messages are not sent to processes when calling UnhookWindowsHookEx.)
By broadcasting WM_NULL to all processes after the injecting process calls UnhookWindowsHookEx the message pump wakes up in the injected processes and the DLL reference count is decremented. The DLL is unloaded immediately when the injected DLL finally calls FreeLibraryAndExitThread.
This is only part of the solution. If the injecting process is killed or crashes, no message is broadcasted so the DLL does not get unloaded from processes that do not have a UI. As I mention before I have a thread running in the DLL that waits on the injecting process handle. When the injecting process ends the DLL is signaled and then calls PostThreadMessage to send WM_NULL to each thread in the process. Then it waits until the DLL reference count is decremented before continuing and cleaning up before calling FreeLibraryAndExitThread. As a result, the DLL is unloaded almost immediately from all processes, UI or no UI.