Suspicious SearchProtocolHost no Command Line Arguments

name: Suspicious SearchProtocolHost no Command Line Arguments
id: f52d2db8-31f9-4aa7-a176-25779effe55c
version: 13
date: '2026-03-25'
author: Michael Haag, Splunk
status: production
type: TTP
description: |-
    The following analytic detects instances of searchprotocolhost.exe running without command line arguments.
    This behavior is unusual and often associated with malicious activities, such as those performed by Cobalt Strike.
    The detection leverages Endpoint Detection and Response (EDR) telemetry, focusing on process execution data.
    This activity is significant because searchprotocolhost.exe typically runs with specific arguments, and its absence may indicate an attempt to evade detection.
    If confirmed malicious, this could lead to unauthorized code execution, potential credential dumping, or other malicious actions within the environment.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |-
    | tstats `security_content_summariesonly`
      count min(_time) as firstTime
            max(_time) as lastTime

    FROM datamodel=Endpoint.Processes WHERE

    (
        Processes.process_name=searchprotocolhost.exe
        OR
        Processes.original_file_name=searchprotocolhost.exe
    )
    Processes.process IN ("*searchprotocolhost","*searchprotocolhost.exe", "*searchprotocolhost.exe\"")

    BY Processes.action Processes.dest Processes.original_file_name
       Processes.parent_process Processes.parent_process_exec
       Processes.parent_process_guid Processes.parent_process_id
       Processes.parent_process_name Processes.parent_process_path
       Processes.process Processes.process_exec Processes.process_guid
       Processes.process_hash Processes.process_id Processes.process_integrity_level
       Processes.process_name Processes.process_path Processes.user
       Processes.user_id Processes.vendor_product

    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `suspicious_searchprotocolhost_no_command_line_arguments_filter`
how_to_implement: |-
    The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives: |-
    No false positives have been identified at this time.
references:
    - https://github.com/mandiant/red_team_tool_countermeasures/blob/master/rules/PGF/supplemental/hxioc/SUSPICIOUS%20EXECUTION%20OF%20SEARCHPROTOCOLHOST%20(METHODOLOGY).ioc
drilldown_searches:
    - name: View the detection results for - "$dest$" and "$user$"
      search: '%original_detection_search% | search  dest = "$dest$" user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$" and "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") 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: Suspicious searchprotocolhost.exe process with no command line arguments executed on $dest$ by $user$
    risk_objects:
        - field: dest
          type: system
          score: 50
        - field: user
          type: user
          score: 50
    threat_objects: []
tags:
    analytic_story:
        - BlackByte Ransomware
        - Cobalt Strike
        - Graceful Wipe Out Attack
        - Cactus Ransomware
        - Hellcat Ransomware
    asset_type: Endpoint
    mitre_attack_id:
        - T1055
    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/T1055/cobalt_strike/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog