Catalyzes the oxidative conversion of Delta(5)-ene-3-beta-hydroxy steroid, and the oxidative conversion of ketosteroids. The 3-beta-HSD enzymatic system plays a crucial role in the biosynthesis of all classes of hormonal steroids. During viral infection, steroid production contributes to virulence by inhibiting the host inflammatory response. a 3beta-hydroxy-Delta(5)-steroid + NAD(+) = a 3-oxo-Delta(5)-steroid + H(+) + NADH a 3-oxo-Delta(5)-steroid = a 3-oxo-Delta(4)-steroid Lipid metabolism; steroid biosynthesis. Belongs to the 3-beta-HSD family.