CloudTrailの証跡とイベント履歴

AWS CloudTrail とは

Event History：無料の90日間検索

# Search event history for who deleted an S3 bucket in the last 7 days
aws cloudtrail lookup-events \
  --lookup-attributes AttributeKey=EventName,AttributeValue=DeleteBucket \
  --start-time $(date -u -d '7 days ago' +%Y-%m-%dT%H:%M:%SZ) \
  --query 'Events[].{Time:EventTime,User:Username,Detail:CloudTrailEvent}' \
  --output table

CloudTrail Trail の作成

# Create a multi-region trail delivering to S3
aws cloudtrail create-trail \
  --name OrgAuditTrail \
  --s3-bucket-name my-cloudtrail-logs-111122223333 \
  --is-multi-region-trail \
  --include-global-service-events \
  --enable-log-file-validation

# Start logging (trails are created in 'paused' state)
aws cloudtrail start-logging --name OrgAuditTrail

管理イベントとデータイベントの比較

# Add data event logging for all S3 objects in a specific bucket
aws cloudtrail put-event-selectors \
  --trail-name OrgAuditTrail \
  --event-selectors '[
    {
      "ReadWriteType": "All",
      "IncludeManagementEvents": true,
      "DataResources": [
        {
          "Type": "AWS::S3::Object",
          "Values": ["arn:aws:s3:::my-sensitive-bucket/"]
        }
      ]
    }
  ]'

CloudTrail と CloudWatch Logs の統合

# Update a trail to also deliver to CloudWatch Logs
aws cloudtrail update-trail \
  --name OrgAuditTrail \
  --cloud-watch-logs-log-group-arn arn:aws:logs:us-east-1:111122223333:log-group:CloudTrail/Logs:* \
  --cloud-watch-logs-role-arn arn:aws:iam::111122223333:role/CloudTrailCWLogsRole

# Create a metric filter for root account login
aws logs put-metric-filter \
  --log-group-name CloudTrail/Logs \
  --filter-name RootLogin \
  --filter-pattern '{$.userIdentity.type = "Root" && $.eventName = "ConsoleLogin"}' \
  --metric-transformations metricName=RootLogins,metricNamespace=CISBenchmark,metricValue=1

グローバルサービスイベント

# Verify that global service events are enabled on a trail
aws cloudtrail get-trail \
  --name OrgAuditTrail \
  --query 'Trail.{MultiRegion:IsMultiRegionTrail,GlobalServiceEvents:IncludeGlobalServiceEvents}'

CloudTrail ログ用の S3 バケットポリシー

# Minimum S3 bucket policy for CloudTrail (abbreviated)
# {
#   "Version": "2012-10-17",
#   "Statement": [
#     {
#       "Sid": "AWSCloudTrailAclCheck",
#       "Effect": "Allow",
#       "Principal": {"Service": "cloudtrail.amazonaws.com"},
#       "Action": "s3:GetBucketAcl",
#       "Resource": "arn:aws:s3:::my-cloudtrail-logs-111122223333"
#     },
#     {
#       "Sid": "AWSCloudTrailWrite",
#       "Effect": "Allow",
#       "Principal": {"Service": "cloudtrail.amazonaws.com"},
#       "Action": "s3:PutObject",
#       "Resource": "arn:aws:s3:::my-cloudtrail-logs-111122223333/AWSLogs/111122223333/*",
#       "Condition": {"StringEquals": {"s3:x-amz-acl": "bucket-owner-full-control"}}
#     }
#   ]
# }

組織 Trail

# Create an organisation trail from the management account
aws cloudtrail create-trail \
  --name OrgCentralTrail \
  --s3-bucket-name central-org-cloudtrail-logs \
  --is-multi-region-trail \
  --is-organization-trail \
  --include-global-service-events \
  --enable-log-file-validation

aws cloudtrail start-logging --name OrgCentralTrail

ログ分析のための Athena 統合

-- Query CloudTrail logs in Athena for IAM policy changes in January 2024
SELECT
  eventtime,
  useridentity.arn AS principal,
  eventname,
  requestparameters
FROM cloudtrail_logs_111122223333
WHERE year = '2024'
  AND month = '01'
  AND eventsource = 'iam.amazonaws.com'
  AND eventname IN ('PutUserPolicy','AttachRolePolicy','CreateUser')
ORDER BY eventtime DESC
LIMIT 100;

イベント履歴とトレイルログのクエリ

試験で重要なCloudTrailのポイント

理解度チェック

レッスンのまとめ