AWS Concurrent Sessions From Different Ips

name: AWS Concurrent Sessions From Different Ips
id: 51c04fdb-2746-465a-b86e-b413a09c9085
version: 10
date: '2026-03-10'
author: Bhavin Patel, Splunk
status: production
type: TTP
description: The following analytic identifies an AWS IAM account with concurrent sessions originating from more than one unique IP address within a 5-minute window. It leverages AWS CloudTrail logs, specifically the `DescribeEventAggregates` event, to detect this behavior. This activity is significant as it may indicate a session hijacking attack, where an adversary uses stolen session cookies to access AWS resources from a different location. If confirmed malicious, this could allow unauthorized access to sensitive corporate resources, leading to potential data breaches or further exploitation within the AWS environment.
data_source:
    - AWS CloudTrail DescribeEventAggregates
search: |-
    `cloudtrail` eventName = DescribeEventAggregates src_ip!="AWS Internal"
      | bin span=5m _time
      | rename user_name as user
      | stats min(_time) as firstTime max(_time) as lastTime values(user_agent) as user_agent values(signature) as signature values(src) as src values(dest) as dest dc(src) as distinct_ip_count
        BY _time user vendor_account
           vendor_region vendor_product
      | where distinct_ip_count > 1
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `aws_concurrent_sessions_from_different_ips_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: A user with concurrent sessions from different Ips may also represent the legitimate use of more than one device. Filter as needed and/or customize the threshold to fit your environment.
references:
    - https://attack.mitre.org/techniques/T1185/
    - https://breakdev.org/evilginx-2-next-generation-of-phishing-2fa-tokens/
    - https://github.com/kgretzky/evilginx2
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: User $user$ has concurrent sessions from more than one unique IP address $src$ in the span of 5 minutes.
    risk_objects:
        - field: user
          type: user
          score: 50
    threat_objects:
        - field: src
          type: ip_address
tags:
    analytic_story:
        - Compromised User Account
        - AWS Identity and Access Management Account Takeover
        - Scattered Lapsus$ Hunters
    asset_type: AWS Account
    mitre_attack_id:
        - T1185
    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/T1185/aws_concurrent_sessions_from_different_ips/cloudtrail.json
          sourcetype: aws:cloudtrail
          source: aws_cloudtrail