Is Splinter's Technique legal in Standard, Modern, and Commander?

Splinter's Technique is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Splinter's Technique

Q: What type of card is Splinter's Technique?

Splinter's Technique is a Sorcery. Its oracle text reads: "Sneak {1}{B} (You may cast this spell for {1}{B} if you also return an unblocked attacker you control to hand during the declare blockers step.) Search your library for a card, put that card into your hand, then shuffle."