Tens of thousands of criminals are thought to have been using Genesis, with several hundred users in the UK.
They could search for potential victims by country, and see what data was available before they made their purchase.
Internet users who want to avoid fraud are advised to keep their computer and phone operating systems up-to-date, to use two-factor authentication (2FA) and strong passwords such as ones involving three random words.
They are also being urged to consider using a password manager.
Additional reporting by Andre Rhoden-Paul