Realm is possibly compromised

Yesterday two players of my realm complained to me about loud Christmas music on my realm and at first I thought that it was a prank but today after hearing more complaints about the loud Christmas music I decided to log onto another account on a different device and then I heard the loud Christmas music, there are no add-ons/resource packs active on my realm and the ones I was using had no trace of the Christmas music in their files, I really want to get rid of this Christmas music so people can play on my realm without having to deal with obnoxiously loud Christmas music but I have no idea what to do about it. I can send an invite to my realm if needed.