Windows COM CLSID Hijacking via Registry Default InprocServer32/LocalServer32 Modification
Detects registry changes to COM CLSID Default InprocServer32/LocalServer32 values that point to suspicious locations.
- Product
- windows
- Category
- registry_set
- Author
- Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
- Published
- 2024-07-16
- Updated
- 2026-07-30
ATT&CK techniques
Persistence → Priv EscRecon
Resource Dev
Initial Access
Execution
Persistence
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule flags Windows registry writes where the TargetObject path contains a CLSID and the Default value under InprocServer32 or LocalServer32 is targeted. Altering these default COM server locations can redirect COM activation to attacker-controlled code, enabling persistence or privilege escalation. It relies on registry_set telemetry, matching the CLSID registry path structure and suspicious value destinations within user-writable or commonly abused locations such as AppData, Temp, Startup, and Perflogs.
Reporting behind it
- microsoft.comhttps://www.microsoft.com/security/blog/2022/07/27/untangling-knotweed-european-private-sector-offensive-actor-using-0-day-exploits/ (idea)
- unit42.paloaltonetworks.comhttps://unit42.paloaltonetworks.com/snipbot-romcom-malware-variant/
- blog.talosintelligence.comhttps://blog.talosintelligence.com/uat-5647-romcom/
- global.ptsecurity.comhttps://global.ptsecurity.com/analytics/pt-esc-threat-intelligence/darkhotel-a-cluster-of-groups-united-by-common-techniques
- threatbook.iohttps://threatbook.io/blog/Analysis-of-APT-C-60-Attack-on-South-Korea
- catalyst.prodaft.comhttps://catalyst.prodaft.com/public/report/inside-the-latest-espionage-campaign-of-nebulous-mantis
- github.comhttps://github.com/rtecCyberSec/BitlockMove
- cert.gov.uahttps://cert.gov.ua/article/6284080
- securelist.comhttps://securelist.com/forumtroll-apt-hacking-team-dante-spyware/117851/
- github.comhttps://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_set/registry_set_persistence_com_hijacking_builtin.yml
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: Windows COM CLSID Hijacking via Registry Default InprocServer32/LocalServer32 Modification
id: f28fbf38-9916-42d2-95af-5595a229ccc1
related:
- id: 3d968d17-ffa4-4bc0-bfdc-f139de76ce77
type: obsolete
- id: a0ff33d8-79e4-4cef-b4f3-9dc4133ccd12
type: obsolete
- id: 790317c0-0a36-4a6a-a105-6e576bf99a14
type: derived
status: experimental
description: This rule flags Windows registry writes where the TargetObject path contains a CLSID and the Default value under InprocServer32 or LocalServer32 is targeted. Altering these default COM server locations can redirect COM activation to attacker-controlled code, enabling persistence or privilege escalation. It relies on registry_set telemetry, matching the CLSID registry path structure and suspicious value destinations within user-writable or commonly abused locations such as AppData, Temp, Startup, and Perflogs.
references:
- https://www.microsoft.com/security/blog/2022/07/27/untangling-knotweed-european-private-sector-offensive-actor-using-0-day-exploits/ (idea)
- https://unit42.paloaltonetworks.com/snipbot-romcom-malware-variant/
- https://blog.talosintelligence.com/uat-5647-romcom/
- https://global.ptsecurity.com/analytics/pt-esc-threat-intelligence/darkhotel-a-cluster-of-groups-united-by-common-techniques
- https://threatbook.io/blog/Analysis-of-APT-C-60-Attack-on-South-Korea
- https://catalyst.prodaft.com/public/report/inside-the-latest-espionage-campaign-of-nebulous-mantis
- https://github.com/rtecCyberSec/BitlockMove
- https://cert.gov.ua/article/6284080
- https://securelist.com/forumtroll-apt-hacking-team-dante-spyware/117851/
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_set/registry_set_persistence_com_hijacking_builtin.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2024-07-16
modified: 2025-11-10
tags:
- attack.privilege-escalation
- attack.persistence
- attack.t1546.015
logsource:
category: registry_set
product: windows
detection:
selection_target_root:
TargetObject|contains: \CLSID\
TargetObject|endswith:
- \InprocServer32\(Default)
- \LocalServer32\(Default)
selection_target_builtin_clsid:
TargetObject|contains:
- \{1f486a52-3cb1-48fd-8f50-b8dc300d9f9d}\
- \{2155fee3-2419-4373-b102-6843707eb41f}\
- \{4590f811-1d3a-11d0-891f-00aa004b2e24}\
- \{4de225bf-cf59-4cfc-85f7-68b90f185355}\
- \{ddc05a5a-351a-4e06-8eaf-54ec1bc2dcea}\
- \{F56F6FDD-AA9D-4618-A949-C1B91AF43B1A}\
- \{F82B4EF1-93A9-4DDE-8015-F7950A1A6E31}\
- \{7849596a-48ea-486e-8937-a2a3009f31a9}\
- \{0b91a74b-ad7c-4a9d-b563-29eef9167172}\
- \{603D3801-BD81-11d0-A3A5-00C04FD706EC}\
- \{30D49246-D217-465F-B00B-AC9DDD652EB7}\
- \{A7A63E5C-3877-4840-8727-C1EA9D7A4D50}\
- \{2227A280-3AEA-1069-A2DE-08002B30309D}\
- \{2DEA658F-54C1-4227-AF9B-260AB5FC3543}\
- \{AA509086-5Ca9-4C25-8F95-589D3C07B48A}\
selection_susp_location_1:
Details|contains:
- :\Perflogs\
- \AppData\Local\
- \Desktop\
- \Downloads\
- \Microsoft\Windows\Start Menu\Programs\Startup\
- \System32\spool\drivers\color\
- \Temporary Internet
- \Users\Public\
- \Windows\Temp\
- "%appdata%"
- "%temp%"
- "%tmp%"
selection_susp_location_2:
- Details|contains|all:
- :\Users\
- \Favorites\
- Details|contains|all:
- :\Users\
- \Favourites\
- Details|contains|all:
- :\Users\
- \Contacts\
- Details|contains|all:
- :\Users\
- \Pictures\
condition: all of selection_target_* and 1 of selection_susp_location_*
falsepositives:
- Unlikely
level: high
license: DRL-1.1