Name:AWS Concurrent Sessions From Different Ips id:51c04fdb-2746-465a-b86e-b413a09c9085 version:12 date:None 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:
| 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
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' analytic_story:['Compromised User Account', 'AWS Identity and Access Management Account Takeover', 'Scattered Lapsus$ Hunters']
