Query: Sigma rule for Detects changes to the PSFactory COM InProcServer32 registry. This technique was used by RomCom to create persistence st
Matching passage: Sigma rule: Detects changes to the PSFactory COM InProcServer32 registry. This technique was used by RomCom to create persistence st. Logsource: windows / registry_set. Rule: title: Potential PSFactoryBuffer COM Hijacking id: 243380fa-11eb-4141-af92-e14925e77c1b status: test description: Detects changes to the PSFactory COM InProcServer32 registry. This technique was used by RomCom to create persistence storing a malicious DLL. references: - https://blogs.blackberry.com/en/2023/06/romcom-resurfaces-targeting-ukraine - https://strontic.github.io/xcyclopedia/library/clsid_C90250F3-4D7D-4991-9B69-A5C5BC1C2AE6.html - https://www.virustotal.com/gui/file/6d3ab9e729bb03ae8ae3fcd824474c5052a165de6cb4c27334969a542c7b261d/detection - https://www.trendmicro.com/en_us/research/23/e/void-rabisu-s-use-of-romcom-backdoor-shows-a-growing-shift-in-th.html author: BlackBerry Threat Research and Intelligence Team - @Joseliyo_Jstnk date: 2023-06-07 modified: 2023-08-17 tags: - attack.privilege-escalation - attack.persistence - attack.t1546.015 logsource: category: registry_set product: windows detection: selection: TargetObject|endswith: \CLSID\{c90250f3-4d7d-4991-9b69-a5c5bc1c2ae6}\InProcServer32\(Default) filter_main: Details: - '%windir%\System32\ActXPrxy.dll' - C:\Windows\System32\ActXPrxy.dll condition: selection and not filter_main falsepositives: - Unknown level: high
Near-miss passage: Sigma rule: Detects attempts to modify the registry using VBScript's CreateObject("Wscript.shell") and RegWrite methods embedded wit. Logsource: windows / ps_script. Rule: title: Registry Modification Attempt Via VBScript - PowerShell id: 2a0a169d-cc66-43ce-9ae2-6e678e54e46a related: - id: 921aa10f-2e74-4cca-9498-98f9ca4d6fdf type: similar - id: 7f4c43f9-b1a5-4c7d-b24a-b41bf3a3ebf2 type: similar status: experimental description: 'Detects attempts to modify the registry using VBScript''s CreateObject("Wscript.shell") and RegWrite methods embedded within PowerShell scripts or commands. Threat actors commonly embed VBScript code within PowerShell to perform registry modifications, attempting to evade detection that monitors for direct registry access through traditional tools. This technique can be used for persistence, defense evasion, and privilege escalation by modifying registry keys without using regedit.exe, reg.exe, or PowerShell''s native registry cmdlets. ' references: - https://www.linkedin.com/posts/mauricefielenbach_livingofftheland-redteam-persistence-activity-7344801774182051843-TE00/ - https://www.nextron-systems.com/2025/07/29/detecting-the-most-popular-mitre-persistence-method-registry-run-keys-startup-folder/ - https://detect.fyi/hunting-fileless-malware-in-the-windows-registry-1339ccde00ad date: 2025-08-13 author: Swachchhanda Shrawan Poudel (Nextron Systems) tags: - attack.persistence - attack.execution - attack.defense-impairment - attack.t1112 - attack.t1059.005 logsource: category: ps_script product: windows detection: selection: ScriptBlockText|contains|all: - CreateObject - Wscript.shell - .RegWrite condition: selection falsepositives: - Some legitimate admin or install scripts may use these processes for registry modifications. level: medium