Pcsx4 | Github Link

The creators claim the project is semi open-source to hide their "proprietary" core, a common tactic used by fake emulators to avoid showing that there is no functional code at all. Why You Should Avoid PCSX4

Downloading the supposed "emulator" often results in your PC being infected with Trojans, ransomware, or crypto-miners . pcsx4 github link

For a safe experience, always verify the status of an emulator on the Emulation General Wiki before downloading any executable. The creators claim the project is semi open-source