@NitefireOP In the past cheaters/hackers made their own accounts and had their own fun that way.
Now that hardware bans have become common place cheaters do 1 of 2 things:
1) Spoof their hardware
2) Play on someone else's account
Option number 1 is the better option in the long run as you can simply create hundreds of fake accounts on a dime with a bot program. However, due to Apex updating their systems every so often, option 2 becomes the better option as updating a spoofing program isn't easy.
How do they get people's account details? Sometimes they get them through information brokers, leaked data files of user passwords from EA servers or other websites/services (as a vast majority of users use identical/similar passwords and account names) or simply buying user data on the cheap.
Then simply plug all that data up to a bot program that tries to login with the account details of players who haven't played since Season 0/1 and enjoy as you now have an indispensable amount of accounts to test your cheats with.
As for yourself, I'd recommend using a long randomly generated password with 2FA enabled being changed every month if you want to stay secure. And check the news if there have been any data leaks from companies whose services you use to be able to immediately change your password.
