Detection rules › Sigma
Network Connection Initiated Via Notepad.EXE
Detects a network connection that is initiated by the "notepad.exe" process. This might be a sign of process injection from a beacon process or something similar. Notepad rarely initiates a network communication except when printing documents for example.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Privilege Escalation | T1055 Process Injection |
| Stealth | T1055 Process Injection |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 3 | Network connection |
Rule body yaml
title: Network Connection Initiated Via Notepad.EXE
id: e81528db-fc02-45e8-8e98-4e84aba1f10b
status: test
description: |
Detects a network connection that is initiated by the "notepad.exe" process.
This might be a sign of process injection from a beacon process or something similar.
Notepad rarely initiates a network communication except when printing documents for example.
references:
- https://web.archive.org/web/20200219102749/https://www.sans.org/cyber-security-summit/archives/file/summit-archive-1492186586.pdf
- https://www.cobaltstrike.com/blog/why-is-notepad-exe-connecting-to-the-internet
author: EagleEye Team
date: 2020-05-14
modified: 2024-02-02
tags:
- attack.privilege-escalation
- attack.command-and-control
- attack.execution
- attack.stealth
- attack.t1055
logsource:
category: network_connection
product: windows
detection:
selection:
Image|endswith: '\notepad.exe'
filter_optional_printing:
DestinationPort: 9100
condition: selection and not 1 of filter_optional_*
falsepositives:
- Printing documents via notepad might cause communication with the printer via port 9100 or similar.
level: high
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_optional_*Stage 1: selection
selection:
Image|endswith: '\notepad.exe'
Stage 2: not filter_optional_printing
filter_optional_printing:
DestinationPort: 9100
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
DestinationPort | eq | 9100 |
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 |
|---|---|---|
Image | ends_with |
|