AWS Exfiltration via DataSync Task

name: AWS Exfiltration via DataSync Task
id: 05c4b09f-ea28-4c7c-a7aa-a246f665c8a2
version: 9
date: '2026-03-10'
author: Bhavin Patel, Splunk
status: production
type: TTP
data_source:
    - AWS CloudTrail CreateTask
description: The following analytic detects the creation of an AWS DataSync task, which could indicate potential data exfiltration. It leverages AWS CloudTrail logs to identify the `CreateTask` event from the DataSync service. This activity is significant because attackers can misuse DataSync to transfer sensitive data from a private AWS location to a public one, leading to data compromise. If confirmed malicious, this could result in unauthorized access to sensitive information, causing severe data breaches and compliance violations.
search: |-
    `cloudtrail` eventName = CreateTask eventSource="datasync.amazonaws.com"
      | rename  requestParameters.*  as *
      | rename user_name as user
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY signature dest user
           user_agent src vendor_account
           vendor_region vendor_product destinationLocationArn
           sourceLocationArn
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `aws_exfiltration_via_datasync_task_filter`
how_to_implement: You must install splunk AWS add on and Splunk App for AWS. This search works with AWS CloudTrail logs.
known_false_positives: It is possible that an AWS Administrator has legitimately created this task for creating backup. Please check the `sourceLocationArn` and `destinationLocationArn` of this task
references:
    - https://labs.nettitude.com/blog/how-to-exfiltrate-aws-ec2-data/
    - https://www.shehackske.com/how-to/data-exfiltration-on-cloud-1606/
drilldown_searches:
    - name: View the detection results for - "$aws_account_id$"
      search: '%original_detection_search% | search  user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") starthoursago=168  | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: DataSync task created on account id - $vendor_account$ by user $user$ from src_ip $src$
    risk_objects:
        - field: user
          type: user
          score: 50
    threat_objects:
        - field: src
          type: ip_address
tags:
    analytic_story:
        - Suspicious AWS S3 Activities
        - Data Exfiltration
        - Hellcat Ransomware
    asset_type: AWS Account
    mitre_attack_id:
        - T1119
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: threat
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1119/aws_exfil_datasync/cloudtrail.json
          sourcetype: aws:cloudtrail
          source: aws_cloudtrail