I think my friend got hacked

My friends and I were talking through the Twitch app and I was waiting for my friends to finish their game. Suddenly one of my friends playing sent a message to me and everyone else at once through the client about joining a discord server for giveaway which seemed like an obvious suspicious link. They weird part though is that my friend was in a team fight when the message was sent. He and my other friends were also confused because they were in the same game as him and they saw that he did not have enough time to type that and continue fighting. My friend is currently trying to find a way to submit a ticket that closely relates to what happened to him but I would appreciate it if we could receive any information or help on this matter. Thank you. Also I have no idea which discussion this should be in, sorry if it is in the incorrect one.