Monitoring system files for changes against a baseline on a regular basis may help detect the possible introduction of malicious code on a system.
Check
Determine whether the system is monitored for unauthorized changes to system files (e.g., *.exe, *.bat, *.com, *.cmd, and *.dll) against a baseline on a weekly basis.
If system files are not monitored for unauthorized changes, this is a finding.
An approved and properly configured solution will contain both a list of baselines that includes all system file locations and a file comparison task that is scheduled to run at least weekly.
Fix
Monitor the system for unauthorized changes to system files (e.g., *.exe, *.bat, *.com, *.cmd, and *.dll) against a baseline on a weekly basis. This can be done with the use of various monitoring tools.