Name:AWS Console Login Failed During MFA Challenge id:55349868-5583-466f-98ab-d3beb321961e version:11 date:None author:Bhavin Patel, Splunk status:production type:TTP Description:The following analytic identifies failed authentication attempts to the AWS Console during the Multi-Factor Authentication (MFA) challenge. It leverages AWS CloudTrail logs, specifically the `additionalEventData` field, to detect when MFA was used but the login attempt still failed. This activity is significant as it may indicate an adversary attempting to access an account with compromised credentials but being thwarted by MFA. If confirmed malicious, this could suggest an ongoing attempt to breach the account, potentially leading to unauthorized access and further attacks if MFA is bypassed. Data_source:
| stats count min(_time) as firstTime max(_time) as lastTime BY signature dest user user_agent src vendor_account vendor_region vendor_product additionalEventData.MFAUsed errorMessage
how_to_implement:The Splunk AWS Add-on is required to utilize this data. The search requires AWS CloudTrail logs. known_false_positives:Legitimate users may miss to reply the MFA challenge within the time window or deny it by mistake. References: -https://attack.mitre.org/techniques/T1621/ -https://aws.amazon.com/what-is/mfa/ 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:['AWS Identity and Access Management Account Takeover', 'Compromised User Account']
