Linux Malware Detect is a malware scanner for Linux released under the GNU GPLv2 license, that is designed around the threats faced in shared hosted environments. Here is a HOWTO to show you the installation on CentOS 6.3.
1) SSH to CentOS server
2) Get the source package
3) Untar the source file
tar xvzf maldetect-current.tar.gz
4) Install Linux Malware Detect
From the step 3, I saw the the folder of source files is maldetect-1.4.1
cd maldetect-1.4.1 ./install.sh
It is /usr/local/maldetect/conf.maldet
5) Modify the config file
Change the email_addr to the email you can receive the scan result.
All other options are well commented, or self-explained.
6) Run the scan command to scan the files under folder /home
maldet --scan-all /home
The result will send to your email changed on step 5.
After installation, it will add a cron job to the system. Do the daily updating and scanning.