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

Status: test
Severity: high
Log source: category process_creation, product linux
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.

Known false positives

Administrative activity directly with root authentication might trigger this rule if it's unnecessarily prefixed with "sh -c" or "bash -c"

MITRE ATT&CK coverage

Tactic	Techniques
Execution	No specific technique

Telemetry coverage

Platform	Record / event type
Linux	Event ID 1: Process Create

Rule body

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

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	starts_with	`bash -c` `sh -c`	`field:"CommandLine" kind:starts_with`
`ParentImage`	ends_with	`/sshd`	`field:"ParentImage" kind:ends_with value:"/sshd"`
`User`	eq	`root`	`field:"user" kind:eq value:"root"`