Only "lag" hack i know of is what they call Chat Spamming through packets. In which someone (not sure if im allowed to link on here) has broken through their encryption and created a packet sniffer program. I just cant find the updated version of it atm as the guy who worked on it i think quit at or around the end of this January.
But as ive searched for hours and hours online for those saying there are no hacks for this game youre sadly wrong. It just seems kept under wraps pretty good for the sake of Riot not fixing it and it seems quite difficult to do with packet editing with hex addresses, etc.