How to Find AWS CloudTrail Trails Missing Alarms for Console Logins Without MFA
Monitoring unauthorized API calls will help reveal application errors and may reduce time to detect malicious activity.
info
This security check is part of the CIS Amazon Web Services Benchmarks and is rated severity medium.
Prerequisites​
This guide assumes that you have already installed and configured Fix Inventory to collect your AWS resources.
Directions​
-
Execute the following
search
command in Fix Inventory Shell:> search is(aws_cloud_trail) and trail_is_multi_region_trail=true and trail_status.is_logging=true with(empty, --> is(aws_cloudwatch_log_group) with(any, --> is(aws_cloudwatch_metric_filter) and filter_pattern~"\(\s*\$\.eventName\s*=\s*\"ConsoleLogin\"\)\s+&&\s+\(\s*\$.additionalEventData\.MFAUsed\s*!=\s*\"Yes\""))
​kind=aws_cloud_trail, ..., region=fixinventory-poweruser
​kind=aws_cloud_trail, ..., account=poweruser-team -
Pipe the
search
command into thedump
command:> search is(aws_cloud_trail) and trail_is_multi_region_trail=true and trail_status.is_logging=true with(empty, --> is(aws_cloudwatch_log_group) with(any, --> is(aws_cloudwatch_metric_filter) and filter_pattern~"\(\s*\$\.eventName\s*=\s*\"ConsoleLogin\"\)\s+&&\s+\(\s*\$.additionalEventData\.MFAUsed\s*!=\s*\"Yes\"")) | dump
​reported:
​ id: /aws/cloudtrail/123
​ name: some-name
​ ctime: '2022-12-05T22:53:14Z'
​ kind: aws_cloud_trail
​ age: 2mo28dThe command output will list the details of all non-compliant
aws_cloud_trail
resources.
Remediation​
Create CloudWatch alarm based on a metric filter for unauthorized API calls.
note
Please refer to the AWS CloudTrail documentation for details.