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Persistence Via Disk Cleanup Handler - Autorun

Detects when an attacker modifies values of the Disk Cleanup Handler in the registry to achieve persistence via autorun. The disk cleanup manager is part of the operating system. It displays the dialog box […] The user has the option of enabling or disabling individual handlers by selecting or clearing their check box in the disk cleanup manager's UI. Although Windows comes with a number of disk cleanup handlers, they aren't designed to handle files produced by other applications. Instead, the disk cleanup manager is designed to be flexible and extensible by enabling any developer to implement and register their own disk cleanup handler. Any developer can extend the available disk cleanup services by implementing and registering a disk cleanup handler.

Detection Query

root:
  TargetObject|contains: \SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\VolumeCaches\
selection_autorun:
  TargetObject|contains: \Autorun
  Details: DWORD (0x00000001)
selection_pre_after:
  TargetObject|contains:
    - \CleanupString
    - \PreCleanupString
  Details|contains:
    - cmd
    - powershell
    - rundll32
    - mshta
    - cscript
    - wscript
    - wsl
    - \Users\Public\
    - \Windows\TEMP\
    - \Microsoft\Windows\Start Menu\Programs\Startup\
condition: root and 1 of selection_*

Author

Nasreddine Bencherchali (Nextron Systems)

Created

2022-07-21

Data Sources

windowsRegistry Set Events

Platforms

windows

References

Tags

attack.persistence

Raw Content

title: Persistence Via Disk Cleanup Handler - Autorun
id: d4e2745c-f0c6-4bde-a3ab-b553b3f693cc
status: test
description: |
    Detects when an attacker modifies values of the Disk Cleanup Handler in the registry to achieve persistence via autorun.
    The disk cleanup manager is part of the operating system.
    It displays the dialog box […] The user has the option of enabling or disabling individual handlers by selecting or clearing their check box in the disk cleanup manager's UI.
    Although Windows comes with a number of disk cleanup handlers, they aren't designed to handle files produced by other applications.
    Instead, the disk cleanup manager is designed to be flexible and extensible by enabling any developer to implement and register their own disk cleanup handler.
    Any developer can extend the available disk cleanup services by implementing and registering a disk cleanup handler.
references:
    - https://persistence-info.github.io/Data/diskcleanuphandler.html
    - https://www.hexacorn.com/blog/2018/09/02/beyond-good-ol-run-key-part-86/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-07-21
modified: 2023-08-17
tags:
    - attack.persistence
logsource:
    category: registry_set
    product: windows
detection:
    root:
        TargetObject|contains: '\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\VolumeCaches\'
    selection_autorun:
        # Launching PreCleanupString / CleanupString programs w/o gui, i.e. while using e.g. /autoclean
        TargetObject|contains: '\Autorun'
        Details: 'DWORD (0x00000001)'
    selection_pre_after:
        TargetObject|contains:
            - '\CleanupString'
            - '\PreCleanupString'
        Details|contains:
            # Add more as you see fit
            - 'cmd'
            - 'powershell'
            - 'rundll32'
            - 'mshta'
            - 'cscript'
            - 'wscript'
            - 'wsl'
            - '\Users\Public\'
            - '\Windows\TEMP\'
            - '\Microsoft\Windows\Start Menu\Programs\Startup\'
    condition: root and 1 of selection_*
falsepositives:
    - Unknown
level: medium