Stale EC2 Instance Removal

Ensure instances stopped for over 90 days are removed

Description

Enable this rule to help with the baseline configuration of Amazon Elastic Compute Cloud (Amazon EC2) instances by checking whether Amazon EC2 instances have been stopped for more than the allowed number of days, according to your organization's standards.

Rationale

Stopped instances that are no longer needed consume resources and may contain outdated configurations or unpatched software. Removing them reduces the attack surface and management overhead.

Impact

Terminating instances is irreversible. Ensure data on the instance is backed up or no longer needed before termination.

Audit Procedure

Using AWS CLI

No specific CLI audit command is provided for this control. Use the console method below.

Using AWS Console

1. Login to the EC2 console at https://console.aws.amazon.com/ec2/.
2. In the left pane, click Instances, click Instances.
3. Select the Instance for review.
4. Under the Details tab.
5. Review the Launch time.

If the Launch time of the selected Instance is greater than 90 days, the Instance has been offline and is considered outdated.

6. Repeat steps no. 3 - 5 to verify the Launch date for the other instances.

Repeat all steps for the other regions. Refer to the remediation procedure below if any of the Launch times are over 90 days.

Expected Result

No stopped instances should have a Launch time older than 90 days. All stopped instances beyond this threshold should be terminated.

Remediation

Using AWS CLI

No specific CLI remediation command is provided for this control. Use the console method below.

Using AWS Console

1. Login to the EC2 console at https://console.aws.amazon.com/ec2/.

2. In the left pane, click Instances, click Instances.

3. Select the Instance for that hasn't been used for over 90 days.

4. Under the Details tab.

5. Click Instance state, click Terminate instance.

6. Click Terminate.

7. Repeat steps no. 3 - 6 the other instances with a launch date equal to or over 90 days.

Repeat all steps for the other regions.

Default Value

AWS does not automatically terminate stopped instances. They remain in the stopped state indefinitely unless terminated.

References

1. https://docs.aws.amazon.com/config/latest/developerguide/ec2-stopped-instance.html

CIS Controls

Profile

Level 1 | Manual