I don’t know if it’s only Indonesia, or if there are any other countries where the people do not have a family name. For sure, only a few of Indonesian races have a family name: Batak, Flores, Chinese and Menado. I’m one of them, I have a last name. In Indonesia, we can tell where you are from by your family name. (For your information, Indonesia has more than 10 races and each race has its own language)
If I’m not mistaken, Malay people from Malaysia and Singapore don’t have a family name either. They usually use BIN for son of…. and BINTI for daughter of…… So, if you see someone from those countries named Mohammad Bin Usman, don’t panic, they have no relation to Osama Bin Ladin.

neither Balinese
I have a last name, siagian
i have too..
Indonesia has more than 100 races and language. and more than 3000 island