CVE-2024-50623 Exploitation Attempt - Cleo

Status: experimental
Severity: high
Log source: category process_creation, product windows
Author: Tanner Filip, Austin Worline, Chad Hudson, Matt Anderson
Source: github.com/SigmaHQ/sigma

Detects exploitation attempt of Cleo's CVE-2024-50623 by looking for a "cmd.exe" process spawning from the Celo software suite with suspicious Powershell commandline.

Known false positives

Unlikely

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1190` Exploit Public-Facing Application

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation

Rule body

title: CVE-2024-50623 Exploitation Attempt - Cleo
id: f007b877-02e3-45b7-8501-1b78c2864029
status: experimental
description: |
    Detects exploitation attempt of Cleo's CVE-2024-50623 by looking for a "cmd.exe" process spawning from the Celo software suite with suspicious Powershell commandline.
references:
    - https://www.huntress.com/blog/threat-advisory-oh-no-cleo-cleo-software-actively-being-exploited-in-the-wild
author: Tanner Filip, Austin Worline, Chad Hudson, Matt Anderson
date: 2024-12-09
tags:
    - attack.initial-access
    - attack.execution
    - attack.t1190
    - cve.2024-50623
    - detection.emerging-threats
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\javaw.exe'
        ParentCommandLine|contains:
            - 'Harmony'
            - 'lexicom'
            - 'VersaLex'
            - 'VLTrader'
        Image|endswith: '\cmd.exe'
        CommandLine|contains:
            - 'powershell'
            - ' -enc '
            - ' -EncodedCommand'
            - '.Download'
    condition: selection
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    ParentImage|endswith: '\javaw.exe'
    ParentCommandLine|contains:
        - 'Harmony'
        - 'lexicom'
        - 'VersaLex'
        - 'VLTrader'
    Image|endswith: '\cmd.exe'
    CommandLine|contains:
        - 'powershell'
        - ' -enc '
        - ' -EncodedCommand'
        - '.Download'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`-EncodedCommand` `-enc` corpus 8 (sigma 6, elastic 2) `.Download` corpus 2 (sigma 2) `powershell` corpus 25 (sigma 24, chronicle 1)	`field:"CommandLine" kind:match`
`Image`	ends_with	`\cmd.exe` corpus 130 (sigma 130)	`field:"Image" kind:ends_with value:"\cmd.exe"`
`ParentCommandLine`	match	`Harmony` `VLTrader` `VersaLex` `lexicom`	`field:"ParentCommandLine" kind:match`
`ParentImage`	ends_with	`\javaw.exe` corpus 7 (sigma 7)	`field:"ParentImage" kind:ends_with value:"\javaw.exe"`