What is xpcproxy?

i have a big problem.. everytime i go on the internet, there is a norton popup saying vulnerability blocked for fake plugin activity. and for application it sais xpcproxy. i trust norton and im not an expert so i got suspicious and tried to delete it. but my computer didnt delete it. it said that it was deleting but it stayed like that forever so i had to force shut down. is there any solution of getting rid of this?? ty so much.