Am I obligated to report the student who leaked the exam, and what is the ruling on my denying knowledge of her?

The student who leaked the exam questions should be advised and reminded of Allah, and warned of the penalty of reporting her if she repeats the act of leaking them. This is because leaking questions harms society by affecting the evaluation of students' levels.

If the student responds and repents, she should be shielded and her name should not be mentioned so that no harm befalls her, as shielding a repenting Muslim is religiously commendable.

However, if she does not respond to the advice and it is believed that she will leak questions in the future, the responsible authorities must be informed about her. This is because shielding her will encourage her to repeat the act, which will cause great corruption. Shielding someone known for corruption or whose sin relates to public rights is detrimental to society.