iCompaas Support

Profile Applicability:

Level 1

Description:

AWS CloudTrail logs all API activity within an AWS account. Monitoring changes to CloudTrail configuration ensures that log collection remains active and tamper-proof.
This control sets up CloudWatch Alarms and SNS notifications to alert security teams when changes occur, such as:

• Creation of a new CloudTrail (CreateTrail)

• Modification of an existing CloudTrail (UpdateTrail)

• Deletion of a CloudTrail (DeleteTrail)

• Stopping CloudTrail logging (StopLogging)

• Starting CloudTrail logging (StartLogging)

Rationale:

CloudTrail logs are crucial for forensic investigations and security monitoring.
By monitoring for changes, organizations can:

• Detect unauthorized tampering with log settings.

• Ensure audit logs remain intact for compliance (SOC 2, HIPAA, PCI DSS).

• Prevent accidental or malicious disabling of CloudTrail logging.

Impact:

• Proactively detects log tampering and security risks.

• Requires additional CloudWatch and SNS configuration.

• May generate noise if frequent trail updates occur (filtering recommended).

Default Value:

• AWS does not alert by default on CloudTrail configuration changes.

• CloudTrail logs these events, but organizations must configure CloudWatch Alarms and SNS notifications.

Pre-Requisites:

1. AWS CloudTrail enabled with multi-region logging.

2. CloudWatch Logs enabled and integrated with CloudTrail.

3. IAM Permissions Required:

   • cloudtrail:DescribeTrails

   • cloudtrail:GetEventSelectors

   • logs:DescribeMetricFilters

   • cloudwatch:DescribeAlarms

   • sns:ListSubscriptionsByTopic

   • logs:PutMetricFilter, cloudwatch:PutMetricAlarm, sns:CreateTopic
     
     

Remediation:

Test Plan:

Using AWS Console

1. Login to the AWS Management Console.

2. Navigate to CloudTrail: AWS CloudTrail Console.
   
   
   
   

3. Verify there is at least one active multi-region CloudTrail trail.

4. Check that CloudTrail logs are sent to CloudWatch Logs.

5. Navigate to CloudWatch Logs: AWS CloudWatch Console.
   
   
   
   

6. Ensure that a metric filter is created for CloudTrail configuration changes.

7. Check CloudWatch Alarms for alerts on CloudTrail configuration changes.
   
   

Implementation Steps:
Using AWS CLI

Step 1: Create a Metric Filter for CloudTrail Configuration Changes

aws logs put-metric-filter --log-group-name <trail-log-group-name> \
--filter-name cloudtrail-cfg-changes-metric \
--metric-transformations metricName=cloudtrail-cfg-changes-metric,metricNamespace="CISBenchmark",metricValue=1 \
--filter-pattern '{ ($.eventName = CreateTrail) || ($.eventName = UpdateTrail) || ($.eventName = DeleteTrail) || ($.eventName = StartLogging) || ($.eventName = StopLogging) }'

aws sns create-topic --name cloudtrail-cfg-changes-alerts

Step 3: Subscribe to SNS Topic

aws sns subscribe --topic-arn <sns-topic-arn> --protocol email --notification-endpoint <[email protected]>

aws cloudwatch put-metric-alarm --alarm-name cloudtrail-cfg-changes-alarm \
--metric-name cloudtrail-cfg-changes-metric --statistic Sum --period 300 \
--threshold 1 --comparison-operator GreaterThanOrEqualToThreshold \
--evaluation-periods 1 --namespace "CISBenchmark" --alarm-actions <sns-topic-arn>

1. Delete CloudWatch Alarm:

   aws cloudwatch delete-alarms --alarm-names cloudtrail-cfg-changes-alarm

2. Remove the metric filter:

   aws logs delete-metric-filter --log-group-name <trail-log-group-name> --filter-name cloudtrail-cfg-changes-metric

3. Delete SNS topic:

   aws sns delete-topic --topic-arn <sns-topic-arn>

References:

• AWS CloudTrail Monitoring with CloudWatch

• AWS IAM Best Practices

CIS Controls Mapping: