For those dealing with PCI-DSS requirements, you may be asked to provide evidences regarding any existing antivirus on your Linux servers.
Sophos provides some details : Do you need antivirus on Linux servers ?
To check the existing version : sudo cat /opt/sophos-av/engine/version
Any running process :
ps -ef |grep savd
More details about installing Sophos antivirus on Linux servers :
Good help found here : https://help.it.ox.ac.uk/viruses/linux/index