Are βαμπιρ and βρικόλακας the same word in modern Greek?

As other answers have pointed out, the vrikolakas is an indigenous Greek creature rising from the grave, with its own mythology, which is only somewhat similar with that of the vampire. Andreas Karkavitsas‘ harrowing novella The Beggar (1897) depicts the associated superstitions in detail.

When I was a kid, as far as I remember, the Vampires of Eastern Europe or Hollywood were rendered as vrikolakas. They now appear to be rendered as vampir. If you are referring to the vampires of western popular culture, as opposed to blood drinking beings that people used to actually be afraid of, vampir is a safe bet.