It's not that old-fashioned.I know the word '' fink'' is old fashion, but he word brown-noser is informal. Employers always have their people among personnel, to know everything about employees, even though it is not related to the work. It is around word. So, in Farsi we say ''Antenna'', or ''eyes and ears of the boss''.
"Snitches" or "upright citizens" depending on your perspective. Is there a severe drought and a stray spark could start a wildfire? Are they burning garbage?