Windows Suspect Process With Authentication Traffic

name: Windows Suspect Process With Authentication Traffic
id: 953322db-128a-4ce9-8e89-56e039e33d98
version: 9
date: '2026-03-10'
author: Steven Dick
status: production
type: Anomaly
description: The following analytic detects executables running from public or temporary locations that are communicating over Windows domain authentication ports/protocols such as LDAP (389), LDAPS (636), and Kerberos (88). It leverages network traffic data to identify processes originating from user-controlled directories. This activity is significant because legitimate applications rarely run from these locations and attempt domain authentication, making it a potential indicator of compromise. If confirmed malicious, attackers could leverage this to access domain resources, potentially leading to further exploitation and lateral movement within the network.
data_source:
    - Sysmon EventID 3
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime values(All_Traffic.process_id) as process_id  from datamodel=Network_Traffic.All_Traffic where All_Traffic.dest_port IN ("88","389","636")  AND All_Traffic.app IN ("*\\users\\*", "*\\programdata\\*", "*\\temp\\*", "*\\Windows\\Tasks\\*", "*\\appdata\\*", "*\\perflogs\\*") by All_Traffic.action All_Traffic.app All_Traffic.dest All_Traffic.dest_ip All_Traffic.dest_port All_Traffic.direction All_Traffic.dvc All_Traffic.protocol All_Traffic.protocol_version All_Traffic.src All_Traffic.src_ip All_Traffic.src_port All_Traffic.transport All_Traffic.user All_Traffic.vendor_product | `drop_dm_object_name(All_Traffic)`  | rex field=app ".*\\\(?<process_name>.*)$" | `security_content_ctime(firstTime)`  | `security_content_ctime(lastTime)` | `windows_suspect_process_with_authentication_traffic_filter`'
how_to_implement: To implement this analytic, Sysmon should be installed in the environment and generating network events for  userland and/or known public writable locations.
known_false_positives: Known applications running from these locations for legitimate purposes. Targeting only kerberos (port 88) may significantly reduce noise.
references:
    - https://attack.mitre.org/techniques/T1069/002/
    - https://book.hacktricks.xyz/network-services-pentesting/pentesting-kerberos-88
drilldown_searches:
    - name: View the detection results for - "$src$" and "$dest$"
      search: '%original_detection_search% | search  src = "$src$" dest = "$dest$" user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$src$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$src$", "$dest$", "$user$") 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: The process $process_name$ on $src$ has been communicating with $dest$ on $dest_port$.
    risk_objects:
        - field: src
          type: system
          score: 20
        - field: dest
          type: system
          score: 20
        - field: user
          type: user
          score: 20
    threat_objects:
        - field: process_name
          type: process_name
tags:
    analytic_story:
        - Active Directory Discovery
    asset_type: Endpoint
    mitre_attack_id:
        - T1087.002
        - T1204.002
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1649/certify_abuse/certify_esc1_abuse_sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog