In this case, some of these problems are non-issues. The exam is a national exam, taken simultaneously all over the country. So a "leaked exam" doesn't really matter once the exam has started since everyone that's supposed to be taking it, is sitting there taking it. The test timing is done on clock. The real one on the wall. Time from 9am to 3pm. Doesn't help if you can pause the program...
As for the internet part, they just need to have bootable USB-sticks, with the exams on them, tagged with the name and ID of the exam taker. The students boot the exam under supervision, and start. The answers are then saved locally onto the stick, and collected at the end of the day. Alternatively, a central exam server is put up locally(with no internet access), the computers connect to that for login/exam saving.
Also, these exams are overseen be at least 2 people at all times, and they're were sensitive to people breaking rules. Carrying a mobile phone is enough to get your exam failed, sometimes even all the exams of that spring/fall nulled. So any activity that's off from the normal test-taking would raise suspicion.