Notepad Password Files Discovery

SIGMA detection rule by The DFIR Report · NOASSERTION

Detects the execution of Notepad to open a file that has the string "password" which may indicate unauthorized access to credentials or suspicious activity.

title: Notepad Password Files Discovery
id: 3b4e950b-a3ea-44d3-877e-432071990709
status: experimental
description: Detects the execution of Notepad to open a file that has the string "password" which may indicate unauthorized access to credentials or suspicious activity.
references:
    - https://thedfirreport.com/2025/02/24/confluence-exploit-leads-to-lockbit-ransomware/
    - https://intel.thedfirreport.com/eventReports/view/57  # Private Report
author: 'The DFIR Report'
tags:
    - attack.discovery
    - attack.t1083
date: 2025-02-21
logsource:
    product: windows
    category: process_creation
detection:
    selection:
        ParentImage|endswith: '\explorer.exe'
        Image|endswith: '\notepad.exe'
        CommandLine|endswith:
        # Note: Commandline to contain a file with the string password and a specific extension
            - 'password*.txt'
            - 'password*.csv'
            - 'password*.doc'
            - 'password*.xls'
    condition: selection
falsepositives:
    - Legitimate use of opening files from remote hosts by administrators or users. However, storing passwords in text readable format could potentially be a violation of the organization's policy. Any match should be investigated further.
level: low

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

de45b078-674f-4028-9adf-c7bb925f6235

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

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Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

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[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

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