Hi,
A site that has been hacked will remain hacked permanently if the flaw that authorized the hacking is not corrected.
Of course, it's essential to correct the flaws in modules that have been identified as problematic.
Delete all unused modules, and uninstall all deactivated and useless modules.
And, of course, clean up anything that doesn't belong there.
Change passwords for all employee accounts after removing unnecessary employees.
Change FTP passwords.
Change the database table prefix if it's named ps_.
And if you need any help, please don't hesitate to contact me. I'll be happy to make you a customized offer.
I've just added an article on the subject if a PrestaShop store is hacked.