Hacker posed as a potential sponsor and sent the YouTuber files including a weaponized .src file (I think he meant .scr file) disguised as a pdf.

Once executed it, it didn't appear to do anything but in the background it shared the YouTuber's cookies/session data with the hacker. With access they changed 2fa and changed his channel to a Tesla channel. He lost over 1000 subscribers and it took him a day or so to get his channel back.