If the links are to the same site then there are two options really.
either 2 people you know have been infected with the same malware which is sending the crap to all on their contact list, or, you've been infected with some malware which is sending mail to you with reply addresses taken from your contact lists.
I would certainly advise that you get both the people you have appeared to receive mails from to do a full scan with both their anti virus and with malwarebytes, but as a precaution I think it might be a good idea if you done the same on your own computer.