Nigerians and Africans in Malaysia?

Very often the Malaysian newspapers publish articles about the Nigerians and Africans is involved illegal wrong doings like fake money, cheating widows/divorcees money, etc right? Why then, daily few hundred are coming in through airport into Malaysia? Who is helping them get illegal student visas? Who is in charge in the Ministry Of Higher Education and Immigration department who approves visas or these jungle fellows who look so old between 40-60 years old always driving new cars with local gals with them? If they are students, why they are not studying in private colleges but always sitting at bus stops and cyber cafes? How come daily they are seen drinking alcohols (beers) at Puchong Steam boat restaurant at Bandar Puteri 7/10 and 7/9 beside mydin corner?