Emerging Threathightest

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

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Launch
Nasreddine Bencherchali (Nextron Systems)Created Wed Aug 30e4556676-fc5c-4e95-8c39-5ef27791541f2023
Emerging Threat
Active Threat

Developed to detect an active or emerging threat. Prioritize investigation of any alerts and correlate with threat intelligence.

Log Source
WindowsFile Event
ProductWindows← raw: windows
CategoryFile Event← raw: file_event

Events for file system activity including creation, modification, and deletion.

Detection Logic
Detection Logic1 selector
detection:
    selection:
        Image|endswith: '\WinRAR.exe'
        TargetFilename|contains: '\AppData\Local\Temp\Rar$'
        TargetFilename|re: '\.[a-zA-Z0-9]{1,4} \.'
    condition: selection
False Positives
Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

MITRE ATT&CK

Other

cve.2023-38331detection.emerging-threats
Rule Metadata
Rule ID
e4556676-fc5c-4e95-8c39-5ef27791541f
Status
test
Level
high
Type
Emerging Threat
Created
Wed Aug 30
Path
rules-emerging-threats/2023/Exploits/CVE-2023-38831/file_event_win_exploit_cve_2023_38331_winrar_susp_double_ext.yml
Raw Tags
attack.executioncve.2023-38331detection.emerging-threats
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