I recently downloaded Emacs 27.2 from one of the mirrors linked from the homepage of Emacs at gnu.org. After extracting the files and running runemacs.exe, Windows warned me that this was an unrecognized app and that running the file could put my computer at risk. Thinking not too much of it, I ran the file anyway. No, I did not verify the signature.
What tipped me off that there might be a problem was the title of the window Emacs ran in: it said "emacs@DESKTOP-2LURKID". 2LURKID is not a name I recognize, and has a rather sinister sound to it (lurking?). As an experiment I downloaded Emacs 27.1 and ran that. Windows did not warn me about running that exe (although the title of the window was still "emacs@DESKTOP-2LURKID"), which makes me think there was something in the 27.2 build.
I've shut off my computer for now until I can figure out if there's a virus or not. Is my concern valid? What is the title of the Emacs window normally? What are some further steps I can take to determine if this was a virus?