What is Malignant Narcissism?

A narcissist is someone who loves themselves and only themselves (google the myth of Narcissus). Narcissistic people believe that they are right all of the time, and refuse to accept responsibility for their actions (they're too perfect to have made a mistake, so it must be someone else's fault). Malignant means bad. With a person, malignant would mean with ill intent. So malignant narcissism, to me would mean a narcissistic person who intentially tries to cause othersto fail, perhaps because they believe it proves their own superiority? I honestly have never heard those two words used together, but that would be my guess.