I just accidentally got a hackerman like you expelled from my daughter's uni. They sent a peer review for a doc but sent it 3 minutes before deadline and was corrupt. Being helpful programmer and teaching daughter I opened it with a hex editor. Top of file referenced /var/www/corruptmyfilecom. Which seems suspicious. It's a also a website for exactly what you suspect. This was for 5% of grade on assignment and meant to boost your grade by rewarding engagement and peer review.

Daughter dug further and found the doc text (so proud) and it was a outline with loren ipsum in it. Dated 3 minutes before the corruption.

This started the chain of events where one student was no longer in class, teacher was flabbergasted at stupidity for zero gain, and then kid not being in school anymore (I guess was not first issue). Uni it department also checked and verified and added to autoscans in monopoly software. Daughter got full credit for assignment since she had noting to peer review.

I should of been suspicious, I haven't seen a corrupted small file in years.

Hackerman is there but so is overly qualified accidental white hat