Conspiracy theories and antisemitic narratives have flooded social media in the wake of an Islamic State-claimed terror attack at a music venue outside Moscow. On March 22, 2024, four gunmen attacked concertgoers at Crocus City Hall, shooting into the crowd and using explosives to set the building on fire, killing at least 130 people and injuring at least 140 others. Hours after the attack, the Amaq News Agency, a propaganda arm of the Islamic State (IS or ISIS), claimed…