LAWRENCE, Kan. (AP) — A former University of Kansas student who hacked the school’s computer system to changing his failing F grades to As has been sentenced to probation.

20-year-old Varun Sarja used a keystroke logger program to change his grades in the 2016-17 school year when he was a freshman studying engineering.

Keystroke loggers enable hackers to obtain usernames and passwords by recording keystrokes on devices.

Sarja, of Olathe, was placed on academic probation in spring 2017. When records revealed he had achieved an A in math, an academic adviser and the math professor investigated.

Sarja pleaded guilty in May to felony identity theft and unlawful computer acts.

During sentencing Monday, Sarja learned he faces an 18-month prison sentence if he violates the terms of his probation.