Detection rules › Sigma

RunMRU Registry Key Deletion - Registry

Status
experimental
Severity
high
Log source
product windows, category registry_delete
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects attempts to delete the RunMRU registry key, which stores the history of commands executed via the run dialog. In the clickfix techniques, the phishing lures instruct users to open a run dialog through (Win + R) and execute malicious commands. Adversaries may delete this key to cover their tracks after executing commands.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 14RegistryEvent (Key and Value Rename)

Rule body yaml

title: RunMRU Registry Key Deletion - Registry
id: 3a9b8c1e-5b2e-4f7a-9d1c-2a7f3b6e1c55
related:
    - id: c11aecef-9c37-45a6-9c07-bc0782f963fd
      type: similar
status: experimental
description: |
    Detects attempts to delete the RunMRU registry key, which stores the history of commands executed via the run dialog.
    In the clickfix techniques, the phishing lures instruct users to open a run dialog through (Win + R) and execute malicious commands.
    Adversaries may delete this key to cover their tracks after executing commands.
references:
    - https://www.zscaler.com/blogs/security-research/coldriver-updates-arsenal-baitswitch-and-simplefix
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-09-25
tags:
    - attack.stealth
    - attack.t1070.003
logsource:
    category: registry_delete
    product: windows
detection:
    selection:
        TargetObject|endswith: '\Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU'
    condition: selection
falsepositives:
    - Unknown
level: high
regression_tests_path: regression_data/rules/windows/registry/registry_delete/registry_delete_runmru/info.yml

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    TargetObject|endswith: '\Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU'

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.

FieldKindValues
TargetObjectends_with
  • \Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU