c/c++ how can i get base address of .exe running process? - c++

Question

Im looking for a method/function that i can use to get base address of "program.exe"+03262C08 -> B4895A0. This address is from Cheat Engine and base address has been found with Pointer scanner. In pointer scanner i can press show module list and there is address of program.exe starting at address 00400000 program.exe. Pointer scanner was scanned for address 09c3000(The address which i want to reach after base address+many offsets[the final address]). This address is base for certain object but i cant reach the address. I'm able to get only base address of exe file at 00400000. I'm trying to add offsets from pointer 03262C08(and the others) but i cant still reach the address. I cant use function FindWindow(). Becouse a name of the program will be changing and it will be redundant to stick with it. I'm using OpenProcess(), EnumProcessModulesEx(), GetModuleFileNameEx() functions. I have tried others as well like GetModuleInformation(),... with the same result. GetModuleHandle() ended with result 0x126 [ERROR_MOD_NOT_FOUND]. I'm using 64 bit OS and I'm trying to get base address of another process.
I can see all processes on local machine and modules of "program" process.
if (!K32EnumProcesses(aProcesses, sizeof(aProcesses), &cbNeeded)) {
return 1;
}
cProcesses = cbNeeded / sizeof(DWORD);
cout << setw(15) << left << "Process ID" << setw(10) << left << "Modules";
cout << setw(30) << left << "Process Name" << endl;
for (i = 0; i < cProcesses; i++) {
if (aProcesses[i] != 0) {
ProcessView::GetProccesses(aProcesses[i], modules, sizeModules, &cModules, &hCurrProcess);
if (hCurrProcess != NULL) {
cout << endl << setw(15) << left << aProcesses[i] << setw(10) << left << cModules;
ProcessView::PrintModuleName(hCurrProcess, modules);
CloseHandle(hCurrProcess);
}
}
}
ProcessView::GetProccesses(cProcesses, modules, sizeModules, &cModules, &hCurrProcess);
system("cls");
ProcessView::PrintModuleNameAll(hCurrProcess, modules, cModules);
I added here definition of function in example from ProcessView.h file that i have created.
static void GetProccesses(_In_ DWORD processID, _Inout_ HMODULE ahModules[], _In_ int sizeModules, _Out_ DWORD* cModules, _Out_ HANDLE* hProcess);
static void PrintModuleName(_In_ HANDLE processID, _In_ HMODULE* modules);
static void PrintModuleNameAll(_In_ HANDLE hProcess, _In_ HMODULE * modules, _In_ DWORD cModules);

Answer 1

Windows has been using Address Space Layout Randomization for about a decade now, but the module base in EXE's is far older than that. Simply ignore it, it's now meaningless.
And don't forget: each process has its own address space. A pointer in one process is meaningless in the other.

Answer 2

To use ReadProcessMemory or WriteProcessMemory on an address which is found via pointer chain on a process and dynamically get the module base address at runtime you need to accomplish these steps:
Find the Process with ToolHelp32Snapshot
Find the Module with ToolHelp32Snapsho
Get a handle to the process with correct permissions
Walk the pointer chain, de-referencing and adding offsets
Then you can Call ReadProcessMemory or WriteProcessMemory
You must run as administrator
For this example I will use a simple assault cube cheat I've made
#include <iostream>
#include <vector>
#include <Windows.h>
#include "proc.h"
int main()
{
//Get ProcId of the target process
DWORD procId = GetProcId(L"ac_client.exe");
//Getmodulebaseaddress
uintptr_t moduleBase = GetModuleBaseAddress(procId, L"ac_client.exe");
//Get Handle to Process
HANDLE hProcess = 0;
hProcess = OpenProcess(PROCESS_ALL_ACCESS, NULL, procId);
//Resolve base address of the pointer chain
uintptr_t dynamicPtrBaseAddr = moduleBase + 0x10f4f4;
std::cout << "DynamicPtrBaseAddr = " << "0x" << std::hex << dynamicPtrBaseAddr << std::endl;
//Resolve our ammo pointer chain
std::vector<unsigned int> ammoOffsets = { 0x374, 0x14, 0x0 };
uintptr_t ammoAddr = FindDMAAddy(hProcess, dynamicPtrBaseAddr, ammoOffsets);
std::cout << "ammoAddr = " << "0x" << std::hex << ammoAddr << std::endl;
//Read Ammo value
int ammoValue = 0;
ReadProcessMemory(hProcess, (BYTE*)ammoAddr, &ammoValue, sizeof(ammoValue), nullptr);
std::cout << "Curent ammo = " << std::dec << ammoValue << std::endl;
//Write to it
int newAmmo = 1337;
WriteProcessMemory(hProcess, (BYTE*)ammoAddr, &newAmmo, sizeof(newAmmo), nullptr);
//Read out again
ReadProcessMemory(hProcess, (BYTE*)ammoAddr, &ammoValue, sizeof(ammoValue), nullptr);
std::cout << "New ammo = " << std::dec << ammoValue << std::endl;
getchar();
return 0;
}
The header file proc.cpp:
DWORD GetProcId(const wchar_t* procName)
{
DWORD procId = 0;
HANDLE hSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
if (hSnap != INVALID_HANDLE_VALUE)
{
PROCESSENTRY32 procEntry;
procEntry.dwSize = sizeof(procEntry);
if (Process32First(hSnap, &procEntry))
{
do
{
if (!_wcsicmp(procEntry.szExeFile, procName))
{
procId = procEntry.th32ProcessID;
break;
}
} while (Process32Next(hSnap, &procEntry));
}
}
CloseHandle(hSnap);
return procId;
}
uintptr_t GetModuleBaseAddress(DWORD procId, const wchar_t* modName)
{
uintptr_t modBaseAddr = 0;
HANDLE hSnap = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE | TH32CS_SNAPMODULE32, procId);
if (hSnap != INVALID_HANDLE_VALUE)
{
MODULEENTRY32 modEntry;
modEntry.dwSize = sizeof(modEntry);
if (Module32First(hSnap, &modEntry))
{
do
{
if (!_wcsicmp(modEntry.szModule, modName))
{
modBaseAddr = (uintptr_t)modEntry.modBaseAddr;
break;
}
} while (Module32Next(hSnap, &modEntry));
}
}
CloseHandle(hSnap);
return modBaseAddr;
}
uintptr_t FindDMAAddy(HANDLE hProc, uintptr_t ptr, std::vector<unsigned int> offsets)
{
uintptr_t addr = ptr;
for (unsigned int i = 0; i < offsets.size(); ++i)
{
ReadProcessMemory(hProc, (BYTE*)addr, &addr, sizeof(addr), 0);
addr += offsets[i];
}
return addr;
}