Suspicious Provlaunch.EXE Child Process

SIGMA detection rule by Nasreddine Bencherchali (Nextron Systems) · NOASSERTION

Detects suspicious child processes of "provlaunch.exe" which might indicate potential abuse to proxy execution.

title: Suspicious Provlaunch.EXE Child Process
id: f9999590-1f94-4a34-a91e-951e47bedefd
related:
    - id: 7f5d1c9a-3e83-48df-95a7-2b98aae6c13c # CLI Generic
      type: similar
    - id: 2a4b3e61-9d22-4e4a-b60f-6e8f0cde6f25 # CLI Registry
      type: similar
    - id: 7021255e-5db3-4946-a8b9-0ba7a4644a69 # Registry
      type: similar
status: test
description: Detects suspicious child processes of "provlaunch.exe" which might indicate potential abuse to proxy execution.
references:
    - https://lolbas-project.github.io/lolbas/Binaries/Provlaunch/
    - https://twitter.com/0gtweet/status/1674399582162153472
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-08-08
tags:
    - attack.stealth
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        ParentImage|endswith: '\provlaunch.exe'
    selection_child:
        - Image|endswith:
              - '\calc.exe'
              - '\cmd.exe'
              - '\cscript.exe'
              - '\mshta.exe'
              - '\notepad.exe'
              - '\powershell.exe'
              - '\pwsh.exe'
              - '\regsvr32.exe'
              - '\rundll32.exe'
              - '\wscript.exe'
        - Image|contains:
              - ':\PerfLogs\'
              - ':\Temp\'
              - ':\Users\Public\'
              - '\AppData\Temp\'
              - '\Windows\System32\Tasks\'
              - '\Windows\Tasks\'
              - '\Windows\Temp\'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

8e5abf9d-2909-415a-97c4-6567847d133a

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

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Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

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