Safari "Adobe Flash Player Update" Mac Virus
I cannot remove this Safari "Adobe Flash Player Update" Mac Virus (screenshot below). I tried to remove it with CleanerOne, StartupDisk Fixer, MacCombo and Malwarebytes. I've reinstalled Catalina OS, and I have followed all steps in this MacSecurity article: https://macsecurity.net/view/227-adobe-flash-player-update-mac-virus to remove suspicious files, multiple times, but I still get this pop up.
Can someone please help me get rid of this? Is this NOT a virus, nor adware, and that is that why I cannot remove it? Please can someone help?
MacBook Pro 13", macOS 10.15