Here are the quick steps to install clamav on Debian.
1) Login to your server
2) Edit /etc/apt/sources.list and add this line at the bottom of the file.
deb http://volatile.debian.org/debian-volatile stable/volatile main contrib non-free
3) Then run “apt-get update; apt-get install clamav”
If you need clamd, you may also want to run apt-get install clamav-daemon