Thank you for your post and welcome to the Community Forum!
If you have received more than one message, firstly please make sure that your response has been sent correctly and that the system is not alerting you for any additional transactions.
I have received this SMS message three times over the last two months. No change in content, amount that the message quotes or anything. I have checked my paypal account and there is no suspicious activity so I think you can safely block this number (the scammer is just trying to confirm your number is active and open a dialog with you - don't).
I should note that if this number is indeed from Paypal then they really need to lift their game. SMS's are no longer considered secure methods of passing information.
