First don't believe on rumors. Only believe the things which you hear from your ears and which you see from your eyes. If someone say you something then tell him/her that you don't want to listen and tell them if you want to tell then the tell the person about whom you want to talk.
If someone has bad intentions about your friend and it might harm him/her then you should talk to your friend about the situation.
If someone has bad intentions about your friend and it might harm him/her then you should talk to your friend about the situation.