Print Processor Registry Autostart

SPLUNK detection rule by Teoderick Contreras, Splunk · Apache-2.0

The following analytic detects suspicious modifications or new entries in the Print Processor registry path. It leverages registry activity data from the Endpoint data model to identify changes in the specified registry path. This activity is significant because the Print Processor registry is known to be exploited by APT groups like Turla for persistence and privilege escalation. If confirmed malicious, this could allow an attacker to execute a malicious DLL payload by restarting the spoolsv.exe process, leading to potential control over the compromised machine.

name: Print Processor Registry Autostart
id: 1f5b68aa-2037-11ec-898e-acde48001122
version: 12
creation_date: '2021-09-29'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects suspicious modifications or new entries in the Print Processor registry path. It leverages registry activity data from the Endpoint data model to identify changes in the specified registry path. This activity is significant because the Print Processor registry is known to be exploited by APT groups like Turla for persistence and privilege escalation. If confirmed malicious, this could allow an attacker to execute a malicious DLL payload by restarting the spoolsv.exe process, leading to potential control over the compromised machine.
data_source:
    - Sysmon EventID 13
search: '| tstats `security_content_summariesonly` count  min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry where Registry.registry_path ="*\\Control\\Print\\Environments\\Windows x64\\Print Processors*" by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product | `security_content_ctime(lastTime)` | `security_content_ctime(firstTime)` | `drop_dm_object_name(Registry)` | `print_processor_registry_autostart_filter`'
how_to_implement: To successfully implement this search, you must be ingesting data that records registry activity from your hosts to populate the endpoint data model in the registry node. This is typically populated via endpoint detection-and-response product, such as Carbon Black or endpoint data sources, such as Sysmon. The data used for this search is typically generated via logs that report reads and writes to the registry.
known_false_positives: possible new printer installation may add driver component on this registry.
references:
    - https://attack.mitre.org/techniques/T1547/012/
    - https://www.welivesecurity.com/2020/05/21/no-game-over-winnti-group/
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"
finding:
    title: modified/added/deleted registry entry $registry_path$ on $dest$
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: modified/added/deleted registry entry $registry_path$ on $dest$
analytic_story:
    - Data Destruction
    - Windows Privilege Escalation
    - Hermetic Wiper
    - Windows Persistence Techniques
asset_type: Endpoint
mitre_attack_id:
    - T1547.012
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/T1547.012/print_reg/sysmon_print.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

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