name: Windows COM Hijacking InprocServer32 Modification
id: b7bd83c0-92b5-4fc7-b286-23eccfa2c561
version: 1
date: '2022-09-26'
author: Michael Haag, Splunk
status: production
type: TTP
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.
data_source:
- Sysmon Event ID 1
search:
  selection1:
    OriginalFileName: reg.exe
  selection2:
    Image|endswith: reg.exe
  selection3:
    CommandLine: '*inprocserver32*'
  condition: (selection1 or selection2) and selection3
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
  confidence: 80
  impact: 80
  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
  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
  risk_score: 64
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1546.015/atomic_red_team/windows-sysmon.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog
    update_timestamp: true