Detection rules › Sigma
User Shell Folders Registry Modification via CommandLine
Detects modifications to User Shell Folders registry values via reg.exe or PowerShell, which could indicate persistence attempts. Attackers may modify User Shell Folders registry values to point to malicious executables or scripts that will be executed during startup. This technique is often used to maintain persistence on a compromised system by ensuring that malicious payloads are executed automatically.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1112 Modify Registry, T1547.001 Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder |
| Privilege Escalation | T1547.001 Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder |
| Defense Impairment | T1112 Modify Registry |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
Rule body yaml
title: User Shell Folders Registry Modification via CommandLine
id: 8f3ab69a-aa22-4943-aa58-e0a52fdf6818
related:
- id: 9c226817-8dc9-46c2-a58d-66655aafd7dc
type: similar
status: experimental
description: |
Detects modifications to User Shell Folders registry values via reg.exe or PowerShell, which could indicate persistence attempts.
Attackers may modify User Shell Folders registry values to point to malicious executables or scripts that will be executed during startup.
This technique is often used to maintain persistence on a compromised system by ensuring that malicious payloads are executed automatically.
references:
- https://www.welivesecurity.com/en/eset-research/muddywater-snakes-riverbank/
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2026-01-05
tags:
- attack.persistence
- attack.privilege-escalation
- attack.defense-impairment
- attack.t1547.001
- attack.t1112
logsource:
category: process_creation
product: windows
detection:
selection_img:
- Image|endswith:
- '\powershell.exe'
- '\pwsh.exe'
- '\reg.exe'
- OriginalFileName:
- 'powershell.exe'
- 'pwsh.dll'
- 'reg.exe'
selection_cli_action:
CommandLine|contains:
- ' add ' # reg.exe modification
- 'New-ItemProperty'
- 'Set-ItemProperty'
- 'si ' # short for Set-ItemProperty
selection_cli_paths_root:
CommandLine|contains:
- '\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders'
- '\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders'
selection_cli_paths_suffix:
CommandLine|contains: 'Startup' # covers both 'Startup' and 'Common Startup'
condition: all of selection_*
falsepositives:
- Usage of reg.exe or PowerShell to modify User Shell Folders for legitimate purposes; but rare.
level: high
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_user_shell_folders_registry_modification/info.yml
simulation:
- type: atomic-red-team
name: Change Startup Folder - HKLM Modify User Shell Folders Common Startup Value
technique: T1547.001
atomic_guid: acfef903-7662-447e-a391-9c91c2f00f7b
Stages and Predicates
Stage 0: condition
all of selection_*Stage 1: selection_img
selection_img:
- Image|endswith:
- '\powershell.exe'
- '\pwsh.exe'
- '\reg.exe'
- OriginalFileName:
- 'powershell.exe'
- 'pwsh.dll'
- 'reg.exe'
Stage 2: selection_cli_action
selection_cli_action:
CommandLine|contains:
- ' add '
- 'New-ItemProperty'
- 'Set-ItemProperty'
- 'si '
Stage 3: selection_cli_paths_root
selection_cli_paths_root:
CommandLine|contains:
- '\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders'
- '\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders'
Stage 4: selection_cli_paths_suffix
selection_cli_paths_suffix:
CommandLine|contains: 'Startup'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
CommandLine | match |
|
Image | ends_with |
|
OriginalFileName | eq |
|