1.3.1 Ensure AIDE is installed (Scored)

Level 1 - Server 
Level 1 - Workstation

AIDE takes a snapshot of filesystem state including modification times, permissions, and file hashes which can then be used to compare against the current state of the filesystem to detect modifications to the system.

By monitoring the filesystem state compromised files can be detected to prevent or limit the exposure of accidental or malicious misconfigurations or modified binaries.

Run the following command and verify aide is installed:

# rpm -q aide 
aide-<version>

Run the following command to install aide:

# yum install aide

Configure AIDE as appropriate for your environment. Consult the AIDE documentation for options.
Initialize AIDE:

# aide --init 
# mv /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz

AIDE stable manual: http://aide.sourceforge.net/stable/manual.html

The prelinking feature can interfere with AIDE because it alters binaries to speed up their start up times. Run prelink -ua to restore the binaries to their prelinked state, thus avoiding false positives from AIDE.