simple tool that uses Windows APIs to trick a process to load a dll to its memory.

OpenProcess : get a handle for a process in memory knowing its PID .
VirtualAllocEx : Allocate memory in a process knowing its handle .
WriteProcessMemory : Write to a memory in a process knowing its handle .
LoadLibraryW : load dll into a process (This is the function that our process need to execute ) .
CreateRemoteThread : Create thread in another process knowing its handle .

first it search for the pid of the process given in arguments and it open a handle to the process to write the path of the dll in its memory , then it create a remote thread calling the function loadlibraryW to import the dll .

bypassing ASLR this works because kernel32 would have the same base address in all process and the same offsets for all the functions , so loadlibrary will have the same address in our process (Inject.exe) and in the process we want to inject to .

Inject.exe process_name Fullpathofdll.dll