Lynis
From James's Wiki
00 03 * * 7 sudo /home/ractive/lynis/lynis audit system --cronjob
00 04 * * 7 mutt -s "Sserver Lynis Report" ractive74@gmail.com < /var/log/lynis-report.dat
for a rpi setup:
https://ownyourbits.com/2017/12/23/security-audit-your-arm-board-with-lynis/