Windows Registry Screensaver Path Value Modified (SCRNSAVE.EXE)
Alerts on registry changes to the SCRNSAVE.EXE screensaver binary path under HKCU.
- Product
- windows
- Category
- registry_event
- Author
- Bartlomiej Czyz @bczyz1, oscd.community (SigmaHQ), DRL 1.1
- Published
- 2020-10-11
- Updated
- 2026-07-30
ATT&CK techniques
Persistence → Priv EscRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule flags modifications to a Windows registry value that contains the configured screensaver binary path for HKEY_CURRENT_USER\Control Panel\Desktop\SCRNSAVE.EXE. Attackers can abuse screensaver execution to persist by redirecting the screensaver binary to attacker-controlled code. The detection relies on registry event telemetry matching the TargetObject ending in the SCRNSAVE.EXE registry path while excluding changes attributed to certain Image processes.
Reporting behind it
- github.comhttps://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.002/T1546.002.md
- welivesecurity.comhttps://www.welivesecurity.com/wp-content/uploads/2017/08/eset-gazer.pdf
- github.comhttps://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_event/registry_event_modify_screensaver_binary_path.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 Registry Screensaver Path Value Modified (SCRNSAVE.EXE)
id: a9759478-0ca8-4d2b-ab0f-0863e6867132
status: test
description: This rule flags modifications to a Windows registry value that contains the configured screensaver binary path for HKEY_CURRENT_USER\Control Panel\Desktop\SCRNSAVE.EXE. Attackers can abuse screensaver execution to persist by redirecting the screensaver binary to attacker-controlled code. The detection relies on registry event telemetry matching the TargetObject ending in the SCRNSAVE.EXE registry path while excluding changes attributed to certain Image processes.
references:
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.002/T1546.002.md
- https://www.welivesecurity.com/wp-content/uploads/2017/08/eset-gazer.pdf
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_event/registry_event_modify_screensaver_binary_path.yml
author: Bartlomiej Czyz @bczyz1, oscd.community, Huntrule Team
date: 2020-10-11
modified: 2021-11-27
tags:
- attack.persistence
- attack.privilege-escalation
- attack.t1546.002
logsource:
category: registry_event
product: windows
detection:
selection:
TargetObject|endswith: \Control Panel\Desktop\SCRNSAVE.EXE
filter:
Image|endswith:
- \rundll32.exe
- \explorer.exe
condition: selection and not filter
falsepositives:
- Legitimate modification of screensaver
level: medium
license: DRL-1.1
related:
- id: 67a6c006-3fbe-46a7-9074-2ba3b82c3000
type: derived