Not sure if this is the origin, but I think it was popularized in the 1989 film "Tango & Cash". After Tango, played by Sylvester Stallone, and Cash, portrayed by Kurt Russell, were thrown into jail and setup in a failed jailbreak attempt, the bad guy Yves Perret (Jack Pallance) locked them in the boiler room with a bunch of felons Tango & Cash had put in jail. Prior to unleashing a can of whoop-ass, their conversation was as follows:\nGabriel Cash: I don't know about you, but I have an aversion to getting F.U.B.A.R...\nRay Tango: What's F.U.B.A.R.?\nGabriel Cash: Fucked-Up Beyond All Recognition.
What is the origin of "foobar"?