Potential PSFactoryBuffer COM Hijacking
Detects changes to the PSFactory COM InProcServer32 registry. This technique was used by RomCom to create persistence storing a malicious DLL.
Sigma rule (View on GitHub)
1title: Potential PSFactoryBuffer COM Hijacking
2id: 243380fa-11eb-4141-af92-e14925e77c1b
3status: test
4description: Detects changes to the PSFactory COM InProcServer32 registry. This technique was used by RomCom to create persistence storing a malicious DLL.
5references:
6 - https://blogs.blackberry.com/en/2023/06/romcom-resurfaces-targeting-ukraine
7 - https://strontic.github.io/xcyclopedia/library/clsid_C90250F3-4D7D-4991-9B69-A5C5BC1C2AE6.html
8 - https://www.virustotal.com/gui/file/6d3ab9e729bb03ae8ae3fcd824474c5052a165de6cb4c27334969a542c7b261d/detection
9 - https://www.trendmicro.com/en_us/research/23/e/void-rabisu-s-use-of-romcom-backdoor-shows-a-growing-shift-in-th.html
10author: BlackBerry Threat Research and Intelligence Team - @Joseliyo_Jstnk
11date: 2023-06-07
12modified: 2023-08-17
13tags:
14 - attack.persistence
15 - attack.t1546.015
16logsource:
17 category: registry_set
18 product: windows
19detection:
20 selection:
21 TargetObject|endswith: '\CLSID\{c90250f3-4d7d-4991-9b69-a5c5bc1c2ae6}\InProcServer32\(Default)'
22 filter_main:
23 Details:
24 - '%windir%\System32\ActXPrxy.dll'
25 - 'C:\Windows\System32\ActXPrxy.dll'
26 condition: selection and not filter_main
27falsepositives:
28 - Unknown
29level: high
References
Related rules
- COM Hijacking via TreatAs
- Potential COM Object Hijacking Via TreatAs Subkey - Registry
- Potential Persistence Using DebugPath
- Potential Persistence Via Scrobj.dll COM Hijacking
- Rundll32 Registered COM Objects