Is my /tmp /usr/tmpDSK secure?

i found user has cron on /var/tmp/ and the file executed is unix malware based clamav scan

why can he run the script on /var/tmp/ ?
is my /tmp secure?

i have run /scripts/securetmp
and this is my fstab

Code:

LABEL=root      /       ext4    errors=remount-ro,usrjquota=quota.user,jqfmt=vfsv0      1       1
none             /dev/shm      tmpfs   defaults                    0 0

/dev/vda2        swap       swap       defaults        0 0
/usr/tmpDSK             /tmp                    ext3    defaults,noauto        0 0
/tmp             /var/tmp                    ext3    defaults,bind,noauto        0 0

and when running /scripts/securetmp again, i get this error:
*** Notice *** No loop module detected
If the loopback block device is built as a module, try running `modprobe loop` as root via ssh and running this script again.
If the loopback block device is built into the kernel itself, you can ignore this message.

my server is KVM vps

 

my server is KVM and not openvz

thanks