You can install ClamAV from within WHM by going to:

cPanel »Manage Plugins >> Click “Install and keep updated” >> Click Save

You can run a scan for all accounts under /home and output the information to a file named clamscan-04-17-15.log by typing:

/usr/local/cpanel/3rdparty/bin/clamscan -ri -f /root/clamscan-04-17-15.log /home

You can also create a cron job by typing the following:

crontab -e

Then you can add the following:

0 9 * * * for i in `awk '!/nobody/{print $2 | "sort | uniq" }' /etc/userdomains | sort | uniq`; do /usr/local/cpanel/3rdparty/bin/clamscan -i -r /home/$i 2>>/dev/null; done >> /root/infections&