Malignant narcissism appears very closely related to sociopathy. However, narcissists care deeply what others think of them. Not all sociopaths are troubled by the fact that everyone they know thinks they're rotten. However, everyone with these serious moral disorders see others as objects to be used, abused and discarded. They tend to be highly envious, and will stop at nothing to get what they want, because they think they deserve it. They don't care whom they hurt, and, oftentimes, take pleasure in the fact they've made someone suffer.
That's why many people use the terms "malignant narcissism" and "sociopathy" interchangeably. A couple of other terms are also becoming popular. One is "empath." This describes the people a malignant personality typically chooses to target. For the most part, they are sensitive souls who care about others, sometimes to a fault. They are "fixers," who like to help people solve their problems. They are peacemakers who like to go along to get along. Empaths also tend to be honest. Sometimes, though, they have trouble standing up for themselves. The narcissist knows how to exploit these traits.
However, in order to do so, she needs the collaboration of one or more "apaths." This term "apath" appears to be a relatively new one. I think we'll be seeing and hearing it more often, because it so aptly describes the apathy some people have while watching another person being abused.
Apaths are really aligned with the narcissist. If they weren't, they'd put up a fight to protect the target. Deep down, they know the situation is unfair. But they don't want to risk their own position at work, or their social standing, if the situation unfolds outside of the workplace.
The apaths can cause a target just as much distress as the sociopath. From a target's perspective, it's extremely confusing to watch all these "nice" people working in tandem with the primary abuser.
I personally think more attention should be given to the so-called apaths. We tend to blame the sociopath for everything that happens. But the situation couldn't have gained momentum without the help of the apaths.