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 &