much less is generally known about...
[grammar]
This is one area (corporate crime) that much less is generally known about than conventional or traditional crime.

I'm a little confused about this part, much less is generally known about.
Much works as a pronoun, kind of like a subject in the clause, right?
So, the clause after 'one area' is an appositive clause?

Question

much less is generally known about...  
[grammar]
This is one area (corporate crime) that much less is generally known about than conventional or traditional crime.

I'm a little confused about this part, much less is generally known about.
Much works as a pronoun, kind of like a subject in the clause, right?
So, the clause after 'one area' is an appositive clause?

Answer

I'm not a professional so I can't tell you the grammar rules, but I can say that the original English sentence is poorly written and confusing. I would rewrite it to say...

"Generally speaking, corporate crime is one area of crime which is much less known, compared to conventional or traditional crime."