VBScript Payload Stored in Registry

Hunt Hypothesis

Detects VBScript content stored into registry keys as seen being used by UNC2452 group

Detection Rule

Sigma (Original)

title: VBScript Payload Stored in Registry
id: 46490193-1b22-4c29-bdd6-5bf63907216f
status: test
description: Detects VBScript content stored into registry keys as seen being used by UNC2452 group
references:
    - https://www.microsoft.com/security/blog/2021/03/04/goldmax-goldfinder-sibot-analyzing-nobelium-malware/
author: Florian Roth (Nextron Systems)
date: 2021-03-05
modified: 2023-08-17
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1547.001
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: 'Software\Microsoft\Windows\CurrentVersion'
        Details|contains:
            - 'vbscript:'
            - 'jscript:'
            - 'mshtml,'
            - 'RunHTMLApplication'
            - 'Execute('
            - 'CreateObject'
            - 'window.close'
    filter:
        TargetObject|contains: 'Software\Microsoft\Windows\CurrentVersion\Run'
    filter_dotnet:
        Image|endswith: '\msiexec.exe'
        TargetObject|contains: '\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\'
        Details|contains:
            - '\Microsoft.NET\Primary Interop Assemblies\Microsoft.mshtml.dll'
            - '<\Microsoft.mshtml,fileVersion='
            - '_mshtml_dll_'
            - '<\Microsoft.mshtml,culture='
    condition: selection and not 1 of filter*
falsepositives:
    - Unknown
level: high

KQL (Azure Sentinel)

imRegistry
| where (RegistryKey contains "Software\\Microsoft\\Windows\\CurrentVersion" and (RegistryValueData contains "vbscript:" or RegistryValueData contains "jscript:" or RegistryValueData contains "mshtml," or RegistryValueData contains "RunHTMLApplication" or RegistryValueData contains "Execute(" or RegistryValueData contains "CreateObject" or RegistryValueData contains "window.close")) and (not((RegistryKey contains "Software\\Microsoft\\Windows\\CurrentVersion\\Run" or (ActingProcessName endswith "\\msiexec.exe" and RegistryKey endswith "\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Installer\\UserData*" and (RegistryValueData contains "\\Microsoft.NET\\Primary Interop Assemblies\\Microsoft.mshtml.dll" or RegistryValueData contains "<\\Microsoft.mshtml,fileVersion=" or RegistryValueData contains "_mshtml_dll_" or RegistryValueData contains "<\\Microsoft.mshtml,culture=")))))

Required Data Sources

False Positive Guidance

• Unknown

MITRE ATT&CK Context

• Tactic: Privilege Escalation
• Tactic: Persistence
• Technique: T1547.001 — T1547.001

References

• https://www.microsoft.com/security/blog/2021/03/04/goldmax-goldfinder-sibot-analyzing-nobelium-malware/
• SigmaHQ Rule