Azure AD High Number Of Failed Authentications From Ip

name: Azure AD High Number Of Failed Authentications From Ip
id: e5ab41bf-745d-4f72-a393-2611151afd8e
version: 12
date: '2026-03-10'
author: Mauricio Velazco, Bhavin Patel, Splunk
status: production
type: TTP
description: The following analytic detects an IP address with 20 or more failed authentication attempts to an Azure AD tenant within 10 minutes. It leverages Azure AD SignInLogs to identify repeated failed logins from the same IP. This behavior is significant as it may indicate a brute force attack aimed at gaining unauthorized access or escalating privileges. If confirmed malicious, the attacker could potentially compromise user accounts, leading to unauthorized access to sensitive information and resources within the Azure environment.
data_source:
    - Azure Active Directory
search: |
    `azure_monitor_aad`
    category=SignInLogs
    properties.status.errorCode=50126
    properties.authenticationDetails{}.succeeded=false
    | rename properties.* as *
    | bin span=10m _time
    | fillnull value=null
    | stats count min(_time) as firstTime max(_time) as lastTime values(dest) as dest values(user) as user values(user_agent) as user_agent by src _time vendor_account vendor_product
    | where count > 20
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `azure_ad_high_number_of_failed_authentications_from_ip_filter`
how_to_implement: You must install the latest version of Splunk Add-on for Microsoft Cloud Services from Splunkbase (https://splunkbase.splunk.com/app/3110/#/details). You must be ingesting Azure Active Directory events into your Splunk environment through an EventHub. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the SignInLogs log category.
known_false_positives: An Ip address with more than 20 failed authentication attempts in the span of 10 minutes may also be triggered by a broken application.
references:
    - https://attack.mitre.org/techniques/T1110/
    - https://attack.mitre.org/techniques/T1110/001/
    - https://attack.mitre.org/techniques/T1110/003/
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: $src$ failed to authenticate more than 20 times in the span of 10 minutes.
    risk_objects:
        - field: user
          type: user
          score: 50
    threat_objects:
        - field: src
          type: ip_address
tags:
    analytic_story:
        - Compromised User Account
        - Azure Active Directory Account Takeover
        - NOBELIUM Group
    asset_type: Azure Tenant
    mitre_attack_id:
        - T1110.001
        - T1110.003
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: identity
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1110.001/azure_ad_high_number_of_failed_authentications_for_user/azuread.log
          source: Azure AD
          sourcetype: azure:monitor:aad