c++ - WriteProcessMemory no error and it don't writes to correct address -

i have little trouble understand here problem is. first read correct value address: part works fine.

 readprocessmemory(phandle, (lpcvoid)(baseaddr + staticoffset), &value, sizeof(dword), &numbytesread);  value += 0x174;  readprocessmemory(phandle, (lpcvoid)value, &value, sizeof(dword), &numbytesread);  value += 0x4;  readprocessmemory(phandle, (lpcvoid)value, &value, sizeof(dword), &numbytesread);  value += 0xc;  readprocessmemory(phandle, (lpcvoid)value, &value, sizeof(dword), &numbytesread);  value += 0x130;  readprocessmemory(phandle, (lpcvoid)value, &value, sizeof(dword), &numbytesread); 

you see lvl 4 pointer , value have correct information. have think, hey let's decrease value 1 , write result in address.

  newvalue = value - 1; //new value dword   std::cout << "writevalue: " << newvalue << std::endl;             if (!writeprocessmemory(phandle, &value, &newvalue, sizeof(dword), null))             {                 std::cout << "oh write error: " << getlasterror() << std::endl;             }              readprocessmemory(phandle, (lpcvoid)value, &value, sizeof(dword), &numbytesread);             std::cout << "after write value: " << value << std::endl; 

now, no error , address value don't change. don't have experience write memory , hope can me.

important: use own processes. learning reverse enginnering.

tell me why downvote, try make bether. thanks

i tried:

writeprocessmemory(phandle, (lpvoid)value, &newvalue, sizeof(dword), null) 

error_invalid_address

487 (0x1e7)  attempt access invalid address. 

& gets address of variable comes after it. ex. &value. you're trying write address of variable value , since value contained in address space of own process means address passed &value may or may not valid in remote process.

you don't need store final readprocessmemory in value. @ moment last readprocessmemory storing actual value want , not address of value. instead have value pointer variable you're trying access in remote process , create new variable hold value you're trying access.

and since put sizeof(dword) parameter in both write , read i'm gonna assume type of value want dword well.

as such:

readprocessmemory(phandle, (lpcvoid)(baseaddr + staticoffset), &value, sizeof(dword), &numbytesread);  value += 0x174;  readprocessmemory(phandle, (lpcvoid)value, &value, sizeof(dword), &numbytesread);  value += 0x4;  readprocessmemory(phandle, (lpcvoid)value, &value, sizeof(dword), &numbytesread);  value += 0xc;  readprocessmemory(phandle, (lpcvoid)value, &value, sizeof(dword), &numbytesread);  value += 0x130;  dword dwvalue = 0;  readprocessmemory(phandle, (lpcvoid)value, &nvalue, sizeof(dword), &numbytesread); 

now value holds address of variable , dwvalue contains value of variable.

however newvalue = value - 1 needs newvalue = dwvalue - 1.

and readprocessmemory(phandle, (lpcvoid)value, &value, sizeof(dword), &numbytesread) needs become readprocessmemory(phandle, (lpcvoid)value, &dwvalue, sizeof(dword), &numbytesread). likewise std::cout << "after write value: " << value << std::endl; needs become std::cout << "after write value: " << dwvalue << std::endl;.

result:

newvalue = dwvalue - 1; //new value dword   std::cout << "writevalue: " << newvalue << std::endl;             if (!writeprocessmemory(phandle, &value, newvalue, sizeof(dword), null))             {                 std::cout << "oh write error: " << getlasterror() << std::endl;             }              readprocessmemory(phandle, (lpcvoid)value, &dwvalue, sizeof(dword), &numbytesread);             std::cout << "after write value: " << dwvalue << std::endl; 

i highly encourage learn more virtual memory, pointers, etc. there's plethora of tutorials online. might take while you'll eventually. luck , happy coding! :)