Here are all the moves that lower your stats when used. I'll list next to the move what Pokemon learns that and Skill Swap:
Attack lowering moves:
Superpower: Mew, Smeargle, Spinda, Deoxys, Deoxys-Attack, Deoxys-Defense, Deoxys-Speed, Reuniclus
Defense lowering moves:
Close Combat: Smeargle, Gallade, Meloetta, Meloetta-Pirouette
Shell Smash: Smeargle
Superpower: Mew, Smeargle, Spinda, Deoxys, Deoxys-Attack, Deoxys-Defense, Deoxys-Speed, Reuniclus
Special Attack lowering moves:
Draco Meteor: Smeargle, Jirachi
Leaf Storm: Exeggcute, Exeggutor, Smeargle, Celebi, Wormadam
Overheat: Mew, Smeargle, Solrock, Victini
Psycho Boost: Smeargle, Lugia, Deoxys, Deoxys-Attack, Deoxys-Defense, Deoxys-Speed
Special Defense lowering moves:
Close Combat: Smeargle, Gallade, Meloetta, Meloetta-Pirouette
Shell Smash: Smeargle
Speed lowering moves:
Curse: Slowpoke, Slowbro, Exeggcute, Exeggutor, Espeon, Slowking, Smeargle, Chimecho, Chingling, Munna, Musharna, Sylveon
Hammer Arm: Smeargle