$ sudo apt-get update
$ sudo apt-get install libclamav7 

libclamav7 is installed in your system.

Make ensure the libclamav7 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libclamav7 *

You will get with libclamav7 package name, version, architecture and description in a table

libclamav7 package basic information: