It's Cyrillic and this is the language of Kazakstan. It's very funny because it says he/she congratulates holy holiday of Muslims, Eid ul-Fitr (wiki it) and it is maximum a week old because it is now holiday of Eid ul-Fitr. I am not kazakh, I couldn't read & understand it fully. It says, he is from NYC, he wishes all the bests and so on...
Thank you! Time to find a Kazakh speaker. The bottle was found on October 21st (more than a week ago) by the way, so we'll need a full translation to see what exactly is going on. You've been a great help.