1200KM / sigma-rule
Network Connection Initiated Via Notepad.EXE — Sigma Rule
Sigma rule e81528db-fc02-45e8-8e98-4e84aba1f10b. Network Connection Initiated Via Notepad.EXE — Sigma Rule. 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.
Rule metadata and linked tags
Author: EagleEye Team. Source status: test; severity: high. Source dates: 2020-05-14 / 2024-02-02.
{
"category": "network_connection",
"product": "windows"
}Pinned original Sigma rule · Detection Rule License 1.1
Source SHA-256: ff5318a5ed4b30eca2dc9b339a48728d44aefc6a941b129bb3349febcb8e535e
Detection logic
Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.
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
False positives
- Printing documents via notepad might cause communication with the printer via port 9100 or similar.
Source references
Connected ecosystem references
Exact source-tagged techniques
Telemetry review
Read the original logsource above, then inspect the linked detection workspaces for technique-level sensor context. No per-rule telemetry equivalence is inferred.
Pinned research references. No browser attack runner, live simulation result or validated detector is asserted. Source mappings and validation limits are preserved. ATT&CK / Atomic provenance · Detection provenance.