I just had some fraudulent withdrawals on my bank account pretending to be paypal. They did the two sub-$1 authorization transactions, then took out $400 then "

I just had some fraudulent withdrawals on my bank account pretending to be paypal. They did the two sub-$1 authorization transactions, then took out $400 then "reversed" it by putting it back into my account... maybe to attract less suspicion and execute a larger fraud later?? Anyway, my bank reversed the withdrawals and I just got to keep the $400 the scammers deposited in.