Gus Poyet appears to have beaten off competition from Cardiff's Ole Gunnar Solskjaer to land the 28-year-old.
Scocco has been a long-term target for Sunderland, who wanted to sign him before his summer switch to Internacional.
He only joined Internacional last summer from Al-Ain after a spell on loan at Newell's, where he had initially started his career.
Earlier this month, the player's father told Radio Gaucha that two English clubs were looking to sign his son, adding: "It's not that Scocco doesn't like Brazilian football, his problem is that he didn't have motivation to keep playing for Internacional, nothing else.
"The problem is with Internacional, not with the Brazilian clubs."