New BgInfo.EXE Custom VBScript Registry Configuration

Hunt Hypothesis

Detects setting of a new registry value related to BgInfo configuration, which can be abused to execute custom VBScript via “BgInfo.exe”

Detection Rule

Sigma (Original)

title: New BgInfo.EXE Custom VBScript Registry Configuration
id: 992dd79f-dde8-4bb0-9085-6350ba97cfb3
related:
    - id: cd277474-5c52-4423-a52b-ac2d7969902f
      type: similar
status: test
description: Detects setting of a new registry value related to BgInfo configuration, which can be abused to execute custom VBScript via "BgInfo.exe"
references:
    - Internal Research
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-08-16
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1112
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: '\Software\Winternals\BGInfo\UserFields\'
        Details|startswith: '4' # WMI
    condition: selection
falsepositives:
    - Legitimate VBScript
level: medium

KQL (Azure Sentinel)

imRegistry
| where RegistryKey endswith "\\Software\\Winternals\\BGInfo\\UserFields*" and RegistryValueData startswith "4"

KQL (Microsoft 365 Defender)

DeviceRegistryEvents
| where RegistryKey endswith "\\Software\\Winternals\\BGInfo\\UserFields*" and RegistryValueData startswith "4"

Required Data Sources

False Positive Guidance

• Legitimate VBScript

MITRE ATT&CK Context

• Tactic: Persistence
• Technique: T1112 — T1112

References

• Internal Research
• SigmaHQ Rule