Sigma rule: CVE-2023-38331 Exploitation Attempt - Suspicious WinRAR Child Process

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-273b9fa25a83, updated 2024-01-22T00:00:00.000Z.

Rule

Title
CVE-2023-38331 Exploitation Attempt - Suspicious WinRAR Child Process
Status
test
Level
high
Author
Nasreddine Bencherchali (Nextron Systems), Andreas Braathen (mnemonic.io)
Date
2023-08-30
Modified
2024-01-22
File
rules-emerging-threats/2023/Exploits/CVE-2023-38831/proc_creation_win_exploit_cve_2023_38831_winrar_child_proc.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects exploitation attempt of CVE-2023-38331 (WinRAR before v6.23), where an attacker can leverage WinRAR to execute arbitrary commands and binaries.

Log source

product
windows
category
process_creation

Detection

selection_parent:
    ParentImage|endswith: '\WinRAR.exe'
selection_folder:
    CommandLine|contains: '\AppData\Local\Temp\Rar$'
selection_double_ext:
    CommandLine|re: '\.[a-zA-Z0-9]{1,4} \.'
selection_binaries:
    # Note: add additional binaries that the attacker might use
    - Image|endswith:
          - '\cmd.exe'
          - '\cscript.exe'
          - '\powershell.exe'
          - '\pwsh.exe'
          - '\wscript.exe'
    - OriginalFileName:
          - 'Cmd.Exe'
          - 'cscript.exe'
          - 'PowerShell.EXE'
          - 'pwsh.dll'
          - 'wscript.exe'
condition: all of selection_*

False positives (as the rule lists them)

  • Unlikely

Tags

  • detection.emerging-threats
  • attack.execution
  • attack.t1203
  • cve.2023-38331

CVEs this rule names

MITRE ATT&CK ids this rule names

Related rules

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2023/Exploits/CVE-2023-38831/proc_creation_win_exploit_cve_2023_38831_winrar_child_proc.yml

Sources and licences

  • SigmaHQ

    "CVE-2023-38331 Exploitation Attempt - Suspicious WinRAR Child Process" by Nasreddine Bencherchali (Nextron Systems), Andreas Braathen (mnemonic.io) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2023/Exploits/CVE-2023-38831/proc_creation_win_exploit_cve_2023_38831_winrar_child_proc.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: CVE-2023-38331 Exploitation Attempt - Suspicious WinRAR Child Process",
entity page, dataset version ref-273b9fa25a83, updated 2024-01-22T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/ec3a3c2f-9bb0-4a9b-8f4b-5ec386544343 (accessed 2026-11-03).
Underlying source: SigmaHQ rule ec3a3c2f-9bb0-4a9b-8f4b-5ec386544343, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.