It is not for anyone to use this software to dream of making money with no effort at all. The ones who benefit from this are obviously the scammers.
How they benefit?
Possibility #1
They might be able to gain access to your PayPal account and wipe off your hard earned money. It will be too late for you to find out by the time you log in to your account.
Possibility #2
Getting your personal details and sell it to third party companies. You might think is harmless, but such emails can worth tons of money. Out of no where you get unwanted spammy promotion emails.
Possibility #3
Fake PayPal website to deceive you to log in for verifying certain transaction that you are unsure. When you at off guard. It is easy to fall for such tricks.
Possibility #4
Illegal activity by using your PayPal account to make money laundering. That will land you into big trouble.