After he later escaped from S.T.A.R. The Parasite began to form a plan to get back at Superman. He began stalking Lois Lane and Jimmy Olsen in an attempt to get to those closest to Superman. The Parasite had taken the form of one of his previous victims, an old man, and was run down in the pandemonium that evening when Lois came to his aide. Not realizing that she was actually in contact with the Parasite, a simple touch was all Rudy needed to get her knowledge of Superman. Rudy was surprised to learn from Lois Superman's secret identity. A new plan formed when he realized how close Superman actually was to Lois, the Parasite decided to take her place and tear him down emotionally by pretending to be a scorned Lois Lane, even having an affair with Luthor in the process.
Action Comics #763
Adventures Of Superman #577