Detection rules › Sigma

Potential Exploitation of CVE-2024-3094 - Suspicious SSH Child Process

Status
test
Severity
high
Log source
product linux, category process_creation
Author
Arnim Rupp, Nasreddine Bencherchali, Thomas Patzke
Source
github.com/SigmaHQ/sigma

Detects potentially suspicious child process of SSH process (sshd) with a specific execution user. This could be a sign of potential exploitation of CVE-2024-3094.

MITRE ATT&CK coverage

TacticTechniques
ExecutionNo specific technique

Event coverage

Rule body yaml

title: Potential Exploitation of CVE-2024-3094 - Suspicious SSH Child Process
id: 9aa27839-e8ba-4d7a-ac1a-746c22c3d1e5
status: test
description: |
    Detects potentially suspicious child process of SSH process (sshd) with a specific execution user. This could be a sign of potential exploitation of CVE-2024-3094.
references:
    - https://github.com/amlweems/xzbot?tab=readme-ov-file#backdoor-demo
author: Arnim Rupp, Nasreddine Bencherchali, Thomas Patzke
date: 2024-04-01
modified: 2024-07-03
tags:
    - attack.execution
    - cve.2024-3094
    - detection.emerging-threats
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        ParentImage|endswith: '/sshd'
        CommandLine|startswith:
            - 'bash -c'
            - 'sh -c'
        User: 'root'
    condition: selection
falsepositives:
    - Administrative activity directly with root authentication might trigger this rule if it's unnecessarily prefixed with "sh -c" or "bash -c"
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    ParentImage|endswith: '/sshd'
    CommandLine|startswith:
        - 'bash -c'
        - 'sh -c'
    User: 'root'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinestarts_with
  • bash -c
  • sh -c
ParentImageends_with
  • /sshd
Usereq
  • root