name: Windows COM Hijacking InprocServer32 Modification
id: b7bd83c0-92b5-4fc7-b286-23eccfa2c561
version: 1
date: '2022-09-26'
author: Michael Haag, Splunk
type: TTP
datamodel:
- Endpoint
description: The following analytic identifies the use of reg.exe performing an add to the InProcServer32, which may be related to COM hijacking.
  Adversaries can use the COM system to insert malicious code that can be executed in place of legitimate software through hijacking the COM references and relationships as a means for persistence. Hijacking a COM object requires a change in the Registry to replace a reference to a legitimate system component which may cause that component to not work when executed. When that system component is executed through normal system operation the adversary's code will be executed instead.
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Endpoint.Processes where `process_reg`
  Processes.process=*inprocserver32* by Processes.dest Processes.user Processes.parent_process_name Processes.process_name
  Processes.process Processes.process_id Processes.parent_process_id
  | `drop_dm_object_name(Processes)` 
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)` 
  | `windows_com_hijacking_inprocserver32_modification_filter`'
how_to_implement: To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.
known_false_positives: False positives may be present and some filtering may be required.
references:
  - https://attack.mitre.org/techniques/T1546/015/
  - https://blog.cluster25.duskrise.com/2022/09/23/in-the-footsteps-of-the-fancy-bear-powerpoint-graphite/
  - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1546.015/T1546.015.md
tags:
  analytic_story:
  - Living Off The Land
  asset_type: Endpoint
  cis20:
  - CIS 3
  - CIS 5
  - CIS 16
  confidence: 80
  context:
  - Source:Endpoint
  - Stage:Execution
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1546.015/atomic_red_team/windows-sysmon.log
  impact: 80
  kill_chain_phases:
  - Exploitation
  message: An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to modify InProcServer32 within the registry.
  mitre_attack_id:
  - T1546.015
  - T1546
  nist:
  - DE.CM
  observable:
  - name: user
    type: User
    role:
    - Victim
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: parent_process_name
    type: Process
    role:
    - Parent Process
  - name: process_name
    type: Process
    role:
    - Child Process
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - UPDATE
  risk_score: 64
  security_domain: endpoint