XOR fluctuation for an overloaded module or stomped shellcode.
[Manager] holds encrypted payload and decoy copies. [Manager::hide_module]
restores the decoy. [Manager::map_module] writes the payload back when
you need to call it.
let mut manager = dmanager::Manager::new();
manager.new_module(base, payload, decoy).unwrap();
manager.map_module(base).unwrap();
manager.hide_module(base).unwrap();