Agent Malloy is Superman's main antagonist in the miniseries/graphic novel Superman: Secret Identity. He is a governtment secret agent, whose top-secret organization seems to be charged with capturing Superman and other super-powered people for study.
He resembles a stereotypical FBI agent, wearing a black suit and sunglasses. He uses clever traps and advanced weapons technology to bring down Superman.
Near the end of the series, an aging Superman had become friends with Malloy, and the Malloy hired Superman to help the government for certain secret missions.