AWS Concurrent Sessions From Different Ips

name: AWS Concurrent Sessions From Different Ips
id: 51c04fdb-2746-465a-b86e-b413a09c9085
version: 12
creation_date: '2023-02-01'
modification_date: '2026-05-13'
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 ("$user$") | 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: 7d
      latest_offset: "0"
finding:
    title: User $user$ has concurrent sessions from more than one unique IP address $src$ in the span of 5 minutes.
    entity:
        field: user
        type: user
        score: 50
threat_objects:
    - field: src
      type: ip_address
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
category: 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
      test_type: unit