Detection rules › Splunk

Windows DLL Search Order Hijacking with iscsicpl

Status
production
Severity
medium
Group by
IntegrityLevel, command_line, computer_name, event_action, original_file_name, parent_command_line, parent_process_guid, parent_process_id, parent_process_name, process_guid, process_hash, process_id, process_name, user, user_id, vendor_product
Author
Michael Haag, Splunk
Source
github.com/splunk/security_content

The following analytic detects DLL search order hijacking involving iscsicpl.exe. It identifies when iscsicpl.exe loads a malicious DLL from a new path, triggering the payload execution. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on child processes spawned by iscsicpl.exe. This activity is significant as it indicates a potential attempt to execute unauthorized code via DLL hijacking. If confirmed malicious, this could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence within the environment.

MITRE ATT&CK coverage

Event coverage

Rule body splunk

name: Windows DLL Search Order Hijacking with iscsicpl
id: f39ee679-3b1e-4f47-841c-5c3c580acda2
version: 13
creation_date: '2022-06-17'
modification_date: '2026-05-13'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic detects DLL search order hijacking involving iscsicpl.exe. It identifies when iscsicpl.exe loads a malicious DLL from a new path, triggering the payload execution. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on child processes spawned by iscsicpl.exe. This activity is significant as it indicates a potential attempt to execute unauthorized code via DLL hijacking. If confirmed malicious, this could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence 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.parent_process_name=iscsicpl.exe `windows_shells`
      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)`
    | `windows_dll_search_order_hijacking_with_iscsicpl_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: False positives may be present, filtering may be required. Remove the Windows Shells macro to determine if other utilities are using iscsicpl.exe.
references:
    - https://github.com/hackerhouse-opensource/iscsicpl_bypassUAC
    - https://github.com/422926799/csplugin/tree/master/bypassUAC
drilldown_searches:
    - name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | 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: An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to elevate access.
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to elevate access.
threat_objects:
    - field: parent_process_name
      type: parent_process_name
    - field: process_name
      type: process_name
analytic_story:
    - Living Off The Land
    - Compromised Windows Host
    - Windows Defense Evasion Tactics
asset_type: Endpoint
mitre_attack_id:
    - T1574.001
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/T1574.001/iscsicpl/iscsicpl-windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.parent_process_name=iscsicpl.exe `windows_shells`
  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

Stage 2: search

| `drop_dm_object_name(Processes)`

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `windows_dll_search_order_hijacking_with_iscsicpl_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.

FieldKindValues
Processes.parent_process_nameeq
  • "iscsicpl.exe"
Processes.process_namein
  • "WindowsTerminal.exe"
  • "bash.exe"
  • "cmd.exe" corpus 77 (elastic 48, splunk 29)
  • "cscript.exe" corpus 25 (elastic 23, splunk 2)
  • "mshta.exe" corpus 31 (elastic 26, splunk 5)
  • "powershell.exe" corpus 104 (elastic 60, splunk 44)
  • "powershell_ise.exe" corpus 50 (splunk 29, elastic 21)
  • "pwsh.exe" corpus 62 (elastic 33, splunk 29)
  • "sh.exe"
  • "wscript.exe" corpus 29 (elastic 28, splunk 1)
  • "wt.exe"