First, you need ClamAV installed on your system

Ubuntu

sudo apt-get install clamav

Centos 7

yum -y install epel-release
yum -y update
yum -y install clamav-server clamav-data clamav-update clamav-filesystem clamav clamav-scanner-systemd clamav-devel clamav-lib clamav-server-systemd

Install malware.expert scanner

wget http://cdn.malware.expert/malware.expert.scanner.sh
chmod 750 malware.expert.scanner.sh

To scan with malware.expert

bash malware.expert.scanner.sh scan /folder

To run scan in background and save into one .txt file

bash malware.expert.scanner.sh scan /folder > result.txt &