Communication To Uncommon Destination Ports — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: medium. Source dates: 2017-03-19 / 2024-03-12.

{
  "category": "network_connection",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 00317526a267ecfceb9c3f64b2f5ee68b49cecb3a2650817d256009af0d2232f

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: Communication To Uncommon Destination Ports
id: 6d8c3d20-a5e1-494f-8412-4571d716cf5c
related:
    - id: 4b89abaa-99fe-4232-afdd-8f9aa4d20382
      type: similar
status: test
description: Detects programs that connect to uncommon destination ports
references:
    - https://docs.google.com/spreadsheets/d/17pSTDNpa0sf6pHeRhusvWG6rThciE8CsXTSlDUAZDyo
author: Florian Roth (Nextron Systems)
date: 2017-03-19
modified: 2024-03-12
tags:
    - attack.persistence
    - attack.command-and-control
    - attack.t1571
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        DestinationPort:
            - 8080
            - 8888
    filter_main_local_ranges:
        DestinationIp|cidr:
            - '127.0.0.0/8'
            - '10.0.0.0/8'
            - '172.16.0.0/12'
            - '192.168.0.0/16'
            - '169.254.0.0/16'
            - '::1/128'  # IPv6 loopback
            - 'fe80::/10'  # IPv6 link-local addresses
            - 'fc00::/7'  # IPv6 private addresses
    filter_optional_sys_directories:
        Image|startswith:
            - 'C:\Program Files\'
            - 'C:\Program Files (x86)\'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://docs.google.com/spreadsheets/d/17pSTDNpa0sf6pHeRhusvWG6rThciE8CsXTSlDUAZDyo