Originally Posted by Warscythes
If is a keylogger then it will log your keys when you are trying to log in your main as well. Unless you are willing to format right after.
@OP: Does this work after a patch? Because Riot's excuse for not having a replay is because you cannot view the replay after a patch and they have a very frequent patches.
There are some temporary measures in place for handling this. Each LOL versions exe is backed up, and version numbers are stored in each replay file. The replay is then opened with the corresponding exe. I have started some work on creating binary diffs, so that these backups are smaller, however I have only been developing this for a couple of weeks (since ~ version 184.108.40.206) so we'll see how it holds up.
Omniphage: Basically, it records network traffic that is sent to the game (in case that makes you paranoid, it does not listen to any other traffic, just the game, not even the lobby client or anywhere you enter login information). Then in order to replay a game, it creates a local server, and tells the client to connect to that. The server then replays all the network traffic back to the client. There are a few other subtlety needed to make this process work smoothly, but thats the general gist of it.