Detection rules › Splunk
Windows Linked Policies In ADSI Discovery
The following analytic detects the use of the [Adsisearcher] type accelerator in PowerShell Script Block Logging (EventCode=4104) to query Active Directory for domain organizational units. This detection leverages PowerShell operational logs to identify script blocks containing [adsisearcher], objectcategory=organizationalunit, and findAll(). This activity is significant as it indicates potential reconnaissance efforts by adversaries to gain situational awareness of the domain structure. If confirmed malicious, this could lead to further exploitation, such as privilege escalation or lateral movement within the network.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Discovery | T1087.002 Account Discovery: Domain Account |
Event coverage
| Provider | Event | Title |
|---|---|---|
| PowerShell | Event ID 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
Rule body splunk
name: Windows Linked Policies In ADSI Discovery
id: 510ea428-4731-4d2f-8829-a28293e427aa
version: 11
creation_date: '2021-08-25'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects the use of the `[Adsisearcher]` type accelerator in PowerShell Script Block Logging (EventCode=4104) to query Active Directory for domain organizational units. This detection leverages PowerShell operational logs to identify script blocks containing `[adsisearcher]`, `objectcategory=organizationalunit`, and `findAll()`. This activity is significant as it indicates potential reconnaissance efforts by adversaries to gain situational awareness of the domain structure. If confirmed malicious, this could lead to further exploitation, such as privilege escalation or lateral movement within the network.
data_source:
- Powershell Script Block Logging 4104
search: |-
`powershell` EventCode=4104 ScriptBlockText = "*[adsisearcher]*" ScriptBlockText = "*objectcategory=organizationalunit*" ScriptBlockText = "*findAll()*"
| fillnull
| stats count min(_time) as firstTime max(_time) as lastTime
BY dest signature signature_id
user_id vendor_product EventID
Guid Opcode Name
Path ProcessID ScriptBlockId
ScriptBlockText
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_linked_policies_in_adsi_discovery_filter`
how_to_implement: The following Hunting analytic requires PowerShell operational logs to be imported. Modify the powershell macro as needed to match the sourcetype or add index. This analytic is specific to 4104, or PowerShell Script Block Logging.
known_false_positives: Administrators or power users may use this command for troubleshooting.
references:
- https://www.welivesecurity.com/2022/04/12/industroyer2-industroyer-reloaded/
- https://medium.com/@pentesttas/discover-hidden-gpo-s-on-active-directory-using-ps-adsi-a284b6814c81
drilldown_searches:
- name: View the detection results for - "$dest$"
search: '%original_detection_search% | search dest = "$dest$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$dest$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | 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"
intermediate_findings:
entities:
- field: dest
type: system
score: 20
message: Windows PowerShell [Adsisearcher] was used user enumeration on $user_id$
analytic_story:
- Data Destruction
- Active Directory Discovery
- Industroyer2
asset_type: Endpoint
mitre_attack_id:
- T1087.002
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1087.002/adsi_discovery/windows-powershell-xml2.log
source: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational
sourcetype: XmlWinEventLog
test_type: unit
Stages and Predicates
Stage 1: search
`powershell` EventCode=4104 ScriptBlockText = "*[adsisearcher]*" ScriptBlockText = "*objectcategory=organizationalunit*" ScriptBlockText = "*findAll()*"
Stage 2: fillnull
| fillnull
Stage 3: stats
| stats count min(_time) as firstTime max(_time) as lastTime
BY dest signature signature_id
user_id vendor_product EventID
Guid Opcode Name
Path ProcessID ScriptBlockId
ScriptBlockText
Stage 4: search
| `security_content_ctime(firstTime)`
Stage 5: search
| `security_content_ctime(lastTime)`
Stage 6: search
| `windows_linked_policies_in_adsi_discovery_filter`
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
ScriptBlockText | eq |
|