Your time and data are worth more than the $30 you’d save. Play it legally, support Atlus, and enjoy the nightmare – without the real-world headaches.
There is no official free version of Catherine: Full Body for PC. The game is a commercial product that costs money to develop, license, and distribute. Any website claiming to offer a “free download” is either hosting pirated content or, more often, trying to infect your computer with malware.