Detection rules › Sigma
CVE-2023-38331 Exploitation Attempt - Suspicious Double Extension File
Detects the creation of a file with a double extension and a space by WinRAR. This could be a sign of exploitation of CVE-2023-38331
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | No specific technique |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 11: FileCreate |
Rule body
title: CVE-2023-38331 Exploitation Attempt - Suspicious Double Extension File
id: e4556676-fc5c-4e95-8c39-5ef27791541f
related:
- id: ec3a3c2f-9bb0-4a9b-8f4b-5ec386544343
type: similar
status: test
description: Detects the creation of a file with a double extension and a space by WinRAR. This could be a sign of exploitation of CVE-2023-38331
references:
- https://www.group-ib.com/blog/cve-2023-38831-winrar-zero-day/
- https://github.com/knight0x07/WinRAR-Code-Execution-Vulnerability-CVE-2023-38831/blob/26ab6c40b6d2c09bb4fc60feaa4a3a90cfd20c23/Part-1-Overview.md
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-08-30
tags:
- attack.execution
- cve.2023-38331
- detection.emerging-threats
logsource:
category: file_event
product: windows
detection:
selection:
Image|endswith: '\WinRAR.exe'
TargetFilename|contains: '\AppData\Local\Temp\Rar$'
TargetFilename|re: '\.[a-zA-Z0-9]{1,4} \.'
condition: selection
falsepositives:
- Unknown
level: high
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
Image|endswith: '\WinRAR.exe'
TargetFilename|contains: '\AppData\Local\Temp\Rar$'
TargetFilename|re: '\.[a-zA-Z0-9]{1,4} \.'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
Image | ends_with |
| field:"Image" kind:ends_with value:"\WinRAR.exe" |
TargetFilename | match |
| field:"TargetFilename" kind:match value:"\AppData\Local\Temp\Rar$" |
TargetFilename | regex_match |
| field:"TargetFilename" kind:regex_match value:".[a-zA-Z0-9]{1,4} ." |