Strange file called "end" appears after i install a game

To be very specific, i started playing an mmorpg called Riders of Icarus published by Nexon America, for some reason when i install the game launcher for nexon games, a strange file which i'm not sure what format it is, called "end" showed up in the E: drive(not sure if it has anything to do with it but originally i almost installed it on the E: because i thought it was where it was supposed to save the game and not the launcher(similar to how steam works) but i cancelled it and the file appeared on the location i was about to install to, since i didn't know what it was and how to even open it and it didn't say anything in properties(size was i think 1kb or something among those lines) i deleted it and tried opening the launcher's installer again and it showed up again(no matter how many times i delete it and re-download it, it shows up again). Could this be anything malicious? i tried running malwarebytes and nothing showed up. I don't really know much about malware and the like so i'm not sure what it is and it wasn't con C: but i deleted it just in case but if anyone can tell me for sure what it is or could be(i can open installer again for it to show up again if needed), maybe i should go back to playing it on steam but i hated having to delete like 100mb worth of screenshots everytime because i used F12 a lot. If anyone have any idea and need any clues about it just ask what you need to know about it and i'm gonna try to get it for you. Thanks in advance