sigmahighHunting

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

T1055

privilege-escalationcommand-and-controlexecutiondefense-evasion

Detection Query

selection:
  Image|endswith: \notepad.exe
filter_optional_printing:
  DestinationPort: 9100
condition: selection and not 1 of filter_optional_*

Author

EagleEye Team

Created

2020-05-14

Data Sources

windowsNetwork Connection Events

Platforms

windows

References

Tags

attack.privilege-escalationattack.command-and-controlattack.executionattack.defense-evasionattack.t1055

Raw Content

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.defense-evasion
    - 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