Detection rules › Sigma

Potential COM Object Hijacking Via TreatAs Subkey - Registry

Status
test
Severity
medium
Log source
product windows, category registry_set
Author
Kutepov Anton, oscd.community
Source
github.com/SigmaHQ/sigma

Detects COM object hijacking via TreatAs subkey

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 13RegistryEvent (Value Set)

Rule body yaml

title: Potential COM Object Hijacking Via TreatAs Subkey - Registry
id: 9b0f8a61-91b2-464f-aceb-0527e0a45020
status: test
description: Detects COM object hijacking via TreatAs subkey
references:
    - https://bohops.com/2018/08/18/abusing-the-com-registry-structure-part-2-loading-techniques-for-evasion-and-persistence/
author: Kutepov Anton, oscd.community
date: 2019-10-23
modified: 2025-10-26
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.015
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains|all:
            - 'HKU\'
            - 'Classes\CLSID\'
            - '\TreatAs'
    filter_main_svchost:
        # Example of target object by svchost
        # TargetObject: HKU\S-1-5-21-1098798288-3663759343-897484398-1001_Classes\CLSID\{0003000A-0000-0000-C000-000000000046}\TreatAs
        Image: 'C:\WINDOWS\system32\svchost.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Maybe some system utilities in rare cases use linking keys for backward compatibility
level: medium
regression_tests_path: regression_data/rules/windows/registry/registry_set/registry_set_persistence_com_key_linking/info.yml
simulation:
    - type: atomic-red-team
      name: COM hijacking via TreatAs
      technique: T1546.015
      atomic_guid: 33eacead-f117-4863-8eb0-5c6304fbfaa9

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    TargetObject|contains|all:
        - 'HKU\'
        - 'Classes\CLSID\'
        - '\TreatAs'

Stage 2: not filter_main_svchost

filter_main_svchost:
    Image: 'C:\WINDOWS\system32\svchost.exe'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
ImageeqC:\WINDOWS\system32\svchost.exe

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
TargetObjectmatch
  • Classes\CLSID\
  • HKU\
  • \TreatAs