Windows Steal Authentication Certificates Certificate Request

Status: production
Severity: low
Group by: Attributes, Requester, action, dest, name
Author: Michael Haag, Splunk
Source: github.com/splunk/security_content

The following analytic detects when a new certificate is requested from Certificate Services - AD CS. It leverages Event ID 4886, which indicates that a certificate request has been received. This activity is significant because unauthorized certificate requests can be part of credential theft or lateral movement tactics. If confirmed malicious, an attacker could use the certificate to impersonate users, gain unauthorized access to resources, or establish persistent access within the environment. Monitoring and correlating this event with other suspicious activities is crucial for identifying potential security incidents.

Known false positives

False positives will be generated based on normal certificate requests. Leave enabled to generate Risk, as this is meant to be an anomaly analytic.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1649` Steal or Forge Authentication Certificates

Telemetry coverage

Provider	Record / event type
Security-Auditing	Event ID 4886: Certificate Services received a certificate request.

Rule body

name: Windows Steal Authentication Certificates Certificate Request
id: 747d7800-2eaa-422d-b994-04d8bb9e06d0
version: 9
creation_date: '2023-02-06'
modification_date: '2026-05-13'
author: Michael Haag, Splunk
status: production
type: Anomaly
description: The following analytic detects when a new certificate is requested from Certificate Services - AD CS. It leverages Event ID 4886, which indicates that a certificate request has been received. This activity is significant because unauthorized certificate requests can be part of credential theft or lateral movement tactics. If confirmed malicious, an attacker could use the certificate to impersonate users, gain unauthorized access to resources, or establish persistent access within the environment. Monitoring and correlating this event with other suspicious activities is crucial for identifying potential security incidents.
data_source:
    - Windows Event Log Security 4886
search: |-
    `wineventlog_security` EventCode=4886
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY dest, name, Requester,
           action, Attributes
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `windows_steal_authentication_certificates_certificate_request_filter`
how_to_implement: To implement this analytic, enhanced Audit Logging must be enabled on AD CS and within Group Policy Management for CS server. See Page 115 of first reference.
known_false_positives: False positives will be generated based on normal certificate requests. Leave enabled to generate Risk, as this is meant to be an anomaly analytic.
references:
    - https://specterops.io/wp-content/uploads/sites/3/2022/06/Certified_Pre-Owned.pdf
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: A certificate was requested by $dest$.
analytic_story:
    - Windows Certificate Services
asset_type: Endpoint
mitre_attack_id:
    - T1649
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: `search`

`wineventlog_security` EventCode=4886

Stage 2: `stats`

| stats count min(_time) as firstTime max(_time) as lastTime
    BY dest, name, Requester,
       action, Attributes

Stage 3: `search`

| `security_content_ctime(firstTime)`

Stage 4: `search`

| `security_content_ctime(lastTime)`

Stage 5: `search`

| `windows_steal_authentication_certificates_certificate_request_filter`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`EventCode`	eq	`4886` corpus 2 (splunk 2)	`field:"EventID" kind:eq value:"4886"`