Sigma rule: Windows Recovery Environment Disabled Via Reagentc

Rule

Title

Windows Recovery Environment Disabled Via Reagentc

Status

experimental

Level

medium

Author

Daniel Koifman (KoifSec), Michael Vilshin

Date

2025-07-31

File

rules/windows/process_creation/proc_creation_win_reagentc_disable_windows_recovery_environment.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects attempts to disable windows recovery environment using Reagentc.
ReAgentc.exe is a command-line tool in Windows used to manage the Windows Recovery Environment (WinRE).
It allows users to enable, disable, and configure WinRE, which is used for troubleshooting and repairing common boot issues.

Log source

product

windows

category

process_creation

Detection

selection_img:   # Example command simulated:  reagentc /disable
    - Image|endswith: '\reagentc.exe'
    - OriginalFileName: 'reagentc.exe'
selection_cli:
    CommandLine|contains|windash: '/disable'
condition: all of selection_*

False positives (as the rule lists them)

• Legitimate administrative activity

Tags

• attack.impact
• attack.t1490

MITRE ATT&CK ids this rule names

• T1490

References

• https://www.elastic.co/security-labs/maas-appeal-an-infostealer-rises-from-the-ashes
• https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/reagentc-command-line-options?view=windows-11

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_reagentc_disable_windows_recovery_environment.yml