Detection rules › Splunk
AdsiSearcher Account Discovery
The following analytic detects the use of the [Adsisearcher] type accelerator in PowerShell to query Active Directory for domain users. It leverages PowerShell Script Block Logging (EventCode=4104) to identify script blocks containing [adsisearcher], objectcategory=user, and .findAll(). This activity is significant as it may indicate an attempt by adversaries or Red Teams to enumerate domain users for situational awareness and Active Directory discovery. If confirmed malicious, this could lead to further reconnaissance, 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: AdsiSearcher Account Discovery
id: de7fcadc-04f3-11ec-a241-acde48001122
version: 13
creation_date: '2021-08-25'
modification_date: '2026-05-13'
author: Teoderick Contreras, Mauricio Velazco, Splunk
status: production
type: TTP
description: The following analytic detects the use of the `[Adsisearcher]` type accelerator in PowerShell to query Active Directory for domain users. It leverages PowerShell Script Block Logging (EventCode=4104) to identify script blocks containing `[adsisearcher]`, `objectcategory=user`, and `.findAll()`. This activity is significant as it may indicate an attempt by adversaries or Red Teams to enumerate domain users for situational awareness and Active Directory discovery. If confirmed malicious, this could lead to further reconnaissance, privilege escalation, or lateral movement within the network.
data_source:
- Powershell Script Block Logging 4104
search: |-
`powershell` EventCode=4104 ScriptBlockText = "*[adsisearcher]*" ScriptBlockText = "*objectcategory=user*" 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)`
| `adsisearcher_account_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://attack.mitre.org/techniques/T1087/002/
- https://www.blackhillsinfosec.com/red-blue-purple/
- https://devblogs.microsoft.com/scripting/use-the-powershell-adsisearcher-type-accelerator-to-search-active-directory/
drilldown_searches:
- name: View the detection results for - "$dest$" and "$user_id$"
search: '%original_detection_search% | search dest = "$dest$" user_id = "$user_id$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$dest$" and "$user_id$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user_id$") | 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: Powershell process have been used for user enumeration on $dest$
entity:
field: user_id
type: user
score: 50
intermediate_findings:
entities:
- field: dest
type: system
score: 50
message: Powershell process have been used for user enumeration on $dest$
analytic_story:
- Industroyer2
- Active Directory Discovery
- CISA AA23-347A
- Data Destruction
- Scattered Lapsus$ Hunters
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/AD_discovery/adsisearcher_powershell.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=user*" 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
| `adsisearcher_account_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 |
|