Malcom scored in the 3-0 win.
The Brazilian said he was "very happy to be a champion and to see this stadium with so many fans. It's my first game at Camp Nou I have my family in the stands and I scored a goal, it's a dream.
"Although it was a friendly I'm very happy, because it's important to start off scoring."
On playing with Leo Messi, Malcom said: "I have no words to define it. He's the best in the world and to start a game with him and that he sets you up a goal makes me very happy."