Windows Multiple Users Fail To Authenticate Wth ExplicitCredentials

name: Windows Multiple Users Fail To Authenticate Wth ExplicitCredentials
id: e61918fa-9ca4-11eb-836c-acde48001122
version: 13
creation_date: '2021-04-14'
modification_date: '2026-05-13'
author: Mauricio Velazco, Splunk
status: production
type: TTP
description: The following analytic identifies a source user failing to authenticate with 30 unique users using explicit credentials on a host. It leverages Windows Event 4648, which is generated when a process attempts an account logon by explicitly specifying account credentials. This detection is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges within an Active Directory environment. If confirmed malicious, this activity could lead to unauthorized access, privilege escalation, and potential compromise of sensitive information.
data_source:
    - Windows Event Log Security 4648
search: |-
    `wineventlog_security` EventCode=4648 Caller_User_Name!=*$ Target_User_Name!=*$
      | bucket span=5m _time
      | stats dc(Target_User_Name) AS unique_accounts values(Target_User_Name) as tried_account values(dest) as dest values(src_ip) as src_ip values(user) as user
        BY _time, Computer, Caller_User_Name
      | where unique_accounts > 30
      | `windows_multiple_users_fail_to_authenticate_wth_explicitcredentials_filter`
how_to_implement: To successfully implement this search, you need to be ingesting Windows Event Logs from domain controllers as well as member servers and workstations. The Advanced Security Audit policy setting `Audit Logon` within `Logon/Logoff` needs to be enabled.
known_false_positives: A source user failing attempting to authenticate multiple users on a host is not a common behavior for regular systems. Some applications, however, may exhibit this behavior in which case sets of users hosts can be added to an allow list. Possible false positive scenarios include systems where several users connect to like Mail servers, identity providers, remote desktop services, Citrix, etc.
references:
    - https://attack.mitre.org/techniques/T1110/003/
    - https://docs.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4648
    - https://docs.microsoft.com/en-us/windows/security/threat-protection/auditing/basic-audit-logon-events
drilldown_searches:
    - name: View the detection results for - "$Computer$"
      search: '%original_detection_search% | search  Computer = "$Computer$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$Computer$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$Computer$") | 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: Potential password spraying attack from $Computer$
    entity:
        field: Computer
        type: system
        score: 50
analytic_story:
    - Active Directory Password Spraying
    - Insider Threat
    - Volt Typhoon
asset_type: Endpoint
mitre_attack_id:
    - T1110.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1110.003/purplesharp_explicit_credential_spray_xml/windows-security.log
          source: XmlWinEventLog:Security
          sourcetype: XmlWinEventLog
      name: True Positive Test
      test_type: unit