Help! All data in mybook live gone and owner password unknown

This is all I get from cat /etc/crontab :

MyBookLive:~# cat /etc/crontab
# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow user	command
17 *	 * * *    root  cd / && run-parts --report /etc/cron.hourly
0 3	     * * *	  root	test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
10 3	 * * 7	  root	test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
20 3	 1 * *	  root	test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly )
#

What other commands should I do from here to see if I’m compromised?