To clarify, there is no legitimate (like a ".exe" file) that can automatically downgrade a PlayStation 4's system firmware. Programs claiming to offer a "one-click" software-only downgrade are typically scams or malware.
If you are looking to change how your PS4 works, consider these safe, verified methods: Ps4 Tool Downgrade V1.00 Exe Download
If you download a file named PS4_Downgrade_V1.00.exe , you are likely downloading one of the following: To clarify, there is no legitimate (like a "