AWS Exfiltration via DataSync Task

Original Source: [splunk source]
Name:AWS Exfiltration via DataSync Task
id:05c4b09f-ea28-4c7c-a7aa-a246f665c8a2
version:5
date:2024-11-14
author:Bhavin Patel, Splunk
status:production
type:TTP
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.
Data_source:
  • -AWS CloudTrail CreateTask
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:'$info_max_time$'
tags:
  analytic_story:
    - 'Suspicious AWS S3 Activities'
    - 'Data Exfiltration'
  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
manual_test:None