Registry Modification for OCI DLL Redirection — Sigma Rule

Rule metadata and linked tags

Author: Swachchhanda Shrawan Poudel (Nextron Systems). Source status: experimental; severity: high. Source dates: 2026-01-24 / not supplied.

{
  "category": "registry_set",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: e2c3187e37e750b09c5133b325408456aac7beffe32dce557a7fafbc102076a6

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Registry Modification for OCI DLL Redirection
id: c0e0bdec-3e3d-47aa-9974-05539c999c89
status: experimental
description: |
    Detects registry modifications related to 'OracleOciLib' and 'OracleOciLibPath' under 'MSDTC' settings.
    Threat actors may modify these registry keys to redirect the loading of 'oci.dll' to a malicious DLL, facilitating phantom DLL hijacking via the MSDTC service.
references:
    - https://www.crowdstrike.com/en-us/blog/4-ways-adversaries-hijack-dlls/
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2026-01-24
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.defense-impairment
    - attack.t1112
    - attack.t1574.001
logsource:
    category: registry_set
    product: windows
detection:
    selection_ocilib:
        TargetObject|endswith: '\SOFTWARE\Microsoft\MSDTC\MTxOCI\OracleOciLib'
    filter_main_ocilib_file:
        # it is looking when oci.dll name is changed to something else like evil.dll
        Details|contains: 'oci.dll'
    selection_ocilibpath:
        TargetObject|endswith: '\SOFTWARE\Microsoft\MSDTC\MTxOCI\OracleOciLibPath'
    filter_main_ocilibpath:
        # it is looking when oci.dll path is changed to something else like 'C:\Windows\Temp\'
        Details|contains: '%SystemRoot%\System32\'
    condition: (selection_ocilib and not filter_main_ocilib_file) or (selection_ocilibpath and not filter_main_ocilibpath)
falsepositives:
    - Unlikely
level: high

Original YAML and metadata in JSON

False positives

• Unlikely

Source references

• https://www.crowdstrike.com/en-us/blog/4-ways-adversaries-hijack-dlls/