Detection rules › Sigma
Notepad Password Files Discovery
Detects the execution of Notepad to open a file that has the string "password" which may indicate unauthorized access to credentials or suspicious activity.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Discovery | T1083 File and Directory Discovery |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
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
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
ParentImage|endswith: '\explorer.exe'
Image|endswith: '\notepad.exe'
CommandLine|endswith:
- 'password*.txt'
- 'password*.csv'
- 'password*.doc'
- 'password*.xls'
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 | ends_with |
|
Image | ends_with |
|
ParentImage | ends_with |
|