Registry Modification for OCI DLL Redirection

 1title: Registry Modification for OCI DLL Redirection
 2id: c0e0bdec-3e3d-47aa-9974-05539c999c89
 3status: experimental
 4description: |
 5    Detects registry modifications related to 'OracleOciLib' and 'OracleOciLibPath' under 'MSDTC' settings.
 6    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.    
 7references:
 8    - https://www.crowdstrike.com/en-us/blog/4-ways-adversaries-hijack-dlls/
 9author: Swachchhanda Shrawan Poudel (Nextron Systems)
10date: 2026-01-24
11tags:
12    - attack.persistence
13    - attack.privilege-escalation
14    - attack.execution
15    - attack.stealth
16    - attack.defense-impairment
17    - attack.t1112
18    - attack.t1574.001
19logsource:
20    category: registry_set
21    product: windows
22detection:
23    selection_ocilib:
24        TargetObject|endswith: '\SOFTWARE\Microsoft\MSDTC\MTxOCI\OracleOciLib'
25    filter_main_ocilib_file:
26        # it is looking when oci.dll name is changed to something else like evil.dll
27        Details|contains: 'oci.dll'
28    selection_ocilibpath:
29        TargetObject|endswith: '\SOFTWARE\Microsoft\MSDTC\MTxOCI\OracleOciLibPath'
30    filter_main_ocilibpath:
31        # it is looking when oci.dll path is changed to something else like 'C:\Windows\Temp\'
32        Details|contains: '%SystemRoot%\System32\'
33    condition: (selection_ocilib and not filter_main_ocilib_file) or (selection_ocilibpath and not filter_main_ocilibpath)
34falsepositives:
35    - Unlikely
36level: high