The Malfoy name has been ruined, but Draco has been allowed back to Hogwarts to finish his 8th year.

Everyone knows what it really is - a test to see if he's to be trusted.

Draco returns to Hogwarts terrified and resigned to a year of being outed and hated. So he keeps away from everyone, even the other Slytherins.

He's set his goal this year to do the best he can in the N.E.W.T.s and finish school. Even if he doesn't know what's going to happen after.