is it from "Game.exe" ? you can try the sample game from the rpg maker official website https://www.rpgmakerweb.com/additional-downloads (RPG Maker VX Ace - Crysalis) and copy the "Game.exe". but i see no difference, even tried scanning both .exe to virustotal and same results. mostly false alarm.
Just a heads up, you might want to prepare to update this soon. It suffers from no-progress bug that is currently under rapid debugging. Scheduled to be fixed on May 1st at 22:00 JST.
It's out, update please. 聖騎士リアナ to v3.5