Linux Remote System Discovery — Sigma Rule

Rule metadata and linked tags

Author: Alejandro Ortuno, oscd.community. Source status: test; severity: low. Source dates: 2020-10-22 / 2021-11-27.

{
  "category": "process_creation",
  "product": "linux"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 8b48e90fd66ff59fe12af188cdd7c23c607352bfa805fc2f973ad6b70d2696b5

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: Linux Remote System Discovery
id: 11063ec2-de63-4153-935e-b1a8b9e616f1
status: test
description: Detects the enumeration of other remote systems.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1018/T1018.md
author: Alejandro Ortuno, oscd.community
date: 2020-10-22
modified: 2021-11-27
tags:
    - attack.discovery
    - attack.t1018
logsource:
    category: process_creation
    product: linux
detection:
    selection_1:
        Image|endswith: '/arp'
        CommandLine|contains: '-a'
    selection_2:
        Image|endswith: '/ping'
        CommandLine|contains:
            - ' 10.' # 10.0.0.0/8
            - ' 192.168.' # 192.168.0.0/16
            - ' 172.16.' # 172.16.0.0/12
            - ' 172.17.'
            - ' 172.18.'
            - ' 172.19.'
            - ' 172.20.'
            - ' 172.21.'
            - ' 172.22.'
            - ' 172.23.'
            - ' 172.24.'
            - ' 172.25.'
            - ' 172.26.'
            - ' 172.27.'
            - ' 172.28.'
            - ' 172.29.'
            - ' 172.30.'
            - ' 172.31.'
            - ' 127.' # 127.0.0.0/8
            - ' 169.254.' # 169.254.0.0/16
    condition: 1 of selection*
falsepositives:
    - Legitimate administration activities
level: low

Original YAML and metadata in JSON

False positives

• Legitimate administration activities

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1018/T1018.md