Just found this info on the cPanel forum and compiled it to give you a step by step guide of how to upgrade to clamAV 0.88
Silversurfer’s update script and 3w guidelines :
Log into ssh and do the following:
1. mv /etc/clamd.conf /etc/clamd.conf.bak
2. mkdir /home/src
3. cd /home/src
4. wget http://www.sprintserve.net/files/clam-updater.tar.gz
5. tar xvzf clam-updater.tar.gz
6. cd clam-updater
7. ./install
8. cd /etc
9. pico clamd.conf
In pico, uncomment the following items:
ScanPE
DetectBrokenExecutables
ScanOLE2
ScanMail
ScanHTML
ScanArchive
and then ctrl-o and ctrl-x to save and exit.
10. now you need to put this line into your exim-conf editor in WHM
go to Main >> Service Configuration >> Exim Configuration Editor and in the first box add
av_scanner = clamd:/var/run/clamav/clamd
this will tell exim the path for the scanning software
11. service exim restart
12. tail -f /var/log/exim_mainlog
watched log to make sure that mail was being delivered.
13. clamscan -V
Should report version 0.88
14. /etc/cron.daily/freshclam
runs freshclam to update the virus definitions
Done!