AWS S3 Bucket Replicated to Another Account

Last updated a month ago on 2025-12-04

Created a year ago on 2024-07-12

About

Identifies the creation or modification of an S3 bucket replication configuration that sends data to a bucket in a different AWS account. Cross-account replication can be used legitimately for backup, disaster recovery, and multi-account architectures, but adversaries with write access to an S3 bucket may abuse replication rules to silently exfiltrate large volumes of data to attacker-controlled accounts. This rule detects "PutBucketReplication" events where the configured destination account differs from the source bucket's account, indicating potential unauthorized cross-account data movement.

Tags

Domain: CloudData Source: AWSData Source: Amazon Web ServicesData Source: AWS S3Use Case: Threat DetectionTactic: ExfiltrationLanguage: eql

Severity

medium

Risk Score

MITRE ATT&CK™

Exfiltration (TA0010)(external, opens in a new tab or window)

↳ Transfer Data to Cloud Account (T1537)(external, opens in a new tab or window)

False Positive Examples

Cross-account S3 replication is common in multi-account AWS Organizations, centralized logging architectures, and disaster-recovery designs. Confirm whether the destination account is an approved replication target. Unexpected replication configuration changes should be treated as suspicious.

License

Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type: Event Correlation Rule
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: filebeat-*logs-aws.cloudtrail-*
Related Integrations: aws(external, opens in a new tab or window)
Query

✄𐘗text code block:
✄𐘗info where event.dataset == "aws.cloudtrail"
   and event.action == "PutBucketReplication"
   and event.outcome == "success"
   and stringContains(aws.cloudtrail.request_parameters, "Account=")

Install detection rules in Elastic Security

Detect AWS S3 Bucket Replicated to Another Account in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).