Network Connection Initiated Via Notepad.EXE

Title: Network Connection Initiated Via Notepad.EXE
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