@Christopher663
Unless it is an inside job, typically if you use a password for your airbnb login that is identical to a password you use on other sites, you can leave yourself vunerable to having your airbnb account compromised.
Once a criminal has a password you use plus your email address, they can run it through software to see what other sites can be entered.
You should check for email breaches on sites such as https://haveibeenpwned.com/
If a criminal enters your airbnb login, what they are interested in is turning your credit card access into cash ; if you are a host - they can attempt to divert valid payments to their account without the genuine host noticing.
If you use airbnb for travelling, they will likely try to book a fake account - one set up by themselves to divert funds to themselves - and make bookings, typically highish value and short notice - rinse and repeat if no-one distrupts them.
It's difficult to ascertain how the breach occured - if you examine your security info on your airbnb account you will see a log of where and when your account was used surreptitiously.