Remediation
If you are using CloudTrails and CloudWatch, perform the following to setup the metric filter, alarm, SNS topic, and subscription:
- Create a metric filter based on filter pattern provided which checks for AWS Configuration changes and the
<cloudtrail_log_group_name>
taken from audit step 1:
aws logs put-metric-filter --log-group-name <cloudtrail_log_group_name> --filter-name <aws_config_changes_metric> --metric-transformations metricName=<aws_config_changes_metric>, metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventSource = config.amazonaws.com) && (($.eventName=StopConfigurationRecorder)||($.eventName=DeleteDeliveryChannel)||($.eventName=PutDeliveryChannel)||($.eventName=PutConfigurationRecorder)) }'
Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together.
- Create an SNS topic that the alarm will notify:
aws sns create-topic --name <sns_topic_name>
Note: you can execute this command once and then re-use the same topic for all monitoring alarms.
- Create an SNS subscription to topic created in step 2:
aws sns subscribe --topic-arn <sns_topic_arn> --protocol <protocol_for_sns> --notification-endpoint <sns_subscription_endpoints>
Note: you can execute this command once and then re-use the SNS subscription for all monitoring alarms.
- Create an alarm that is associated with the CloudWatch Logs Metric Filter created in step 1 and an SNS topic created in step 2:
aws cloudwatch put-metric-alarm --alarm-name <aws_config_changes_alarm> --metric-name <aws_config_changes_metric> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns_topic_arn>