Not up-to-date with the modern trends, but back in the days Bulgaria was used as a punch-line in various jokes that required a nationality to make fun of.

One of my favorites was in an episode of ALF (80s sitcom), where Alf watches the Miss Universe contest:
-- Hey! That's Benny Hill!! Oh wait, miss Bulgaria ...

A lot of other shows also used it. I can't remember the particular joke now, but something along the lines of "the Bulgarian national (soccer?) team being a bunch of drunken lumberjacks" was used in Murphy Brown.