RDS-Advanced Security offers a System Audit located on the AdminTool dashboard.
The icon on the System Audit button turns red when an issue has been found. Please review them carefully.
When you click on the system audit tile, you can see that it monitors:
The Minimum Password Length audit rule is implemented to alert administrators that an account may not have a password, which make intrusion very likely to happen in case the machine is facing the internet.
Please modify the minimum password length on your server, under Local Policy/Account Policies/Password Policy, to fix this major security issue: