Diabolique
Les Diaboliques (original)
Starring Véra Clouzot, Simone Signoret, Jean Brochard, Pierre Larquey, Michel Serrault, Paul Meurisse, Charles Vanel, Yves-Marie Maurin, Georges Poujouly, Thérèse Dorny
It's a drama and horror movie, and has a rating of 8.1 out of 10 from Imdb which is very high for this kind of movie.
Watch it here
Not found streaming from Finland.