splunk_escuTTP

AWS Exfiltration via EC2 Snapshot

The following analytic detects a series of AWS API calls related to EC2 snapshots within a short time window, indicating potential exfiltration via EC2 Snapshot modifications. It leverages AWS CloudTrail logs to identify actions such as creating, describing, and modifying snapshot attributes. This activity is significant as it may indicate an attacker attempting to exfiltrate data by sharing EC2 snapshots externally. If confirmed malicious, the attacker could gain access to sensitive information stored in the snapshots, leading to data breaches and potential compliance violations.

MITRE ATT&CK

T1537

Detection Query

`cloudtrail` eventName IN ("CreateSnapshot", "DescribeSnapshotAttribute", "ModifySnapshotAttribute", "DeleteSnapshot") src_ip !="guardduty.amazonaws.com"
  | bin _time span=5m
  | rename user_name as user
  | stats count dc(signature) as distinct_api_calls values(signature) as signature values(dest) as dest values(requestParameters.attributeType) as attributeType values(requestParameters.createVolumePermission.add.items{}.userId) as aws_account_id_added values(user_agent) as user_agent
    BY _time user src
       vendor_account vendor_region vendor_product
  | where distinct_api_calls >= 2
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | `aws_exfiltration_via_ec2_snapshot_filter`

Author

Bhavin Patel, Splunk

Created

2026-03-10

Data Sources

AWS CloudTrail CreateSnapshotAWS CloudTrail DescribeSnapshotAttributeAWS CloudTrail ModifySnapshotAttributeAWS CloudTrail DeleteSnapshot

References

Tags

Suspicious Cloud Instance ActivitiesData Exfiltration

Raw Content

name: AWS Exfiltration via EC2 Snapshot
id: ac90b339-13fc-4f29-a18c-4abbba1f2171
version: 8
date: '2026-03-10'
author: Bhavin Patel, Splunk
status: production
type: TTP
data_source:
    - AWS CloudTrail CreateSnapshot
    - AWS CloudTrail DescribeSnapshotAttribute
    - AWS CloudTrail ModifySnapshotAttribute
    - AWS CloudTrail DeleteSnapshot
description: The following analytic detects a series of AWS API calls related to EC2 snapshots within a short time window, indicating potential exfiltration via EC2 Snapshot modifications. It leverages AWS CloudTrail logs to identify actions such as creating, describing, and modifying snapshot attributes. This activity is significant as it may indicate an attacker attempting to exfiltrate data by sharing EC2 snapshots externally. If confirmed malicious, the attacker could gain access to sensitive information stored in the snapshots, leading to data breaches and potential compliance violations.
search: |-
    `cloudtrail` eventName IN ("CreateSnapshot", "DescribeSnapshotAttribute", "ModifySnapshotAttribute", "DeleteSnapshot") src_ip !="guardduty.amazonaws.com"
      | bin _time span=5m
      | rename user_name as user
      | stats count dc(signature) as distinct_api_calls values(signature) as signature values(dest) as dest values(requestParameters.attributeType) as attributeType values(requestParameters.createVolumePermission.add.items{}.userId) as aws_account_id_added values(user_agent) as user_agent
        BY _time user src
           vendor_account vendor_region vendor_product
      | where distinct_api_calls >= 2
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `aws_exfiltration_via_ec2_snapshot_filter`
how_to_implement: You must install splunk AWS add on and Splunk App for AWS. This search works with AWS CloudTrail logs. We have intentionally removed `guardduty.amazonaws.com` from src_ip to remove false positives caused by guard duty. We recommend you adjust the time window as per your environment.
known_false_positives: It is possible that an AWS admin has legitimately shared a snapshot with an other account for a specific purpose. Please check any recent change requests filed in your organization.
references:
    - https://labs.nettitude.com/blog/how-to-exfiltrate-aws-ec2-data/
    - https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_ModifySnapshotAttribute.html
    - https://bleemb.medium.com/data-exfiltration-with-native-aws-s3-features-c94ae4d13436
    - https://stratus-red-team.cloud/attack-techniques/list/
drilldown_searches:
    - name: View the detection results for - "$user$"
      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: Potential AWS EC2 Exfiltration detected 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 Cloud Instance Activities
        - Data Exfiltration
    asset_type: EC2 Snapshot
    mitre_attack_id:
        - T1537
    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/T1537/aws_snapshot_exfil/aws_cloudtrail_events.json
          sourcetype: aws:cloudtrail
          source: aws_cloudtrail