As an AWS specialist in a big organization, you are managing a large number of Linux-based EC2 instances in several AWS accounts. In order to follow the company security policies, you are looking for a method to automatically detect whether the instances are configured securely. The method should be able to check if root login over SSH and password authentication over SSH are disabled. Which of the following methods is the easiest one?

Answer options:

A.Create a Lambda function that loops through all Linux-based instances and checks the file /etc/ssh/sshd_config to see if SSH root login and password authentication over SSH are disabled.
B.Create an Amazon Inspector assessment and include the “Security Best Practices-1.0 rule package” which can determine if root login over SSH and password authentication over SSH are disabled.
C.Configure a rule in AWS Config to check if root login over SSH and password authentication over SSH are disabled in EC2 instances. Raise an SNS notification if the rule is not-compliant.
D.Make sure that the Amazon Linux AMIs are used for EC2 instances. By default, root login over SSH and password authentication over SSH are disabled in Amazon issued AMIs.

Correct Answer : B
Option A is incorrect because you have to create a Lambda function and configure a schedule to run the Lambda function. It is not the easiest method.
Option B is CORRECT because the “Security Best Practices-1.0 rule package” in Amazon Inspector includes the required checks. Amazon Inspector can run an assessment on all the required EC2 instances periodically.
Option C is incorrect because there is no existing AWS Config rule that can do this task. You have to create a custom rule with a Lambda function. It is not as easy as option
B.Option D is incorrect because there are a big number of instances and some of them may use Redhat, Ubuntu or other operating systems. It would be not realistic to use Amazon AMIs for all these EC2 instances.
Reference:
https://docs.aws.amazon.com/inspector/latest/userguide/inspector_security-best-practices.html