ADSI-Cache File Creation By Unusual Utility (via file_event)

This rule detects the creation of an "Active Directory Schema Cache File" (.sch) file by an uncommon tool.

SigmamediumWindowsv1
sigma
title: ADSI-Cache File Creation By Unusual Utility (via file_event)
id: c3695010-1b3f-5a2c-a95a-eaac31b501c4
status: stable
description: This rule detects the creation of an "Active Directory Schema Cache File" (.sch) file by an uncommon tool.
references:
    - https://attack.mitre.org/techniques/T1001/003/
    - https://medium.com/@ivecodoe/detecting-ldapfragger-a-newly-released-cobalt-strike-beacon-using-ldap-for-c2-communication-c274a7f00961
    - https://blog.fox-it.com/2020/03/19/ldapfragger-command-and-control-over-ldap-attributes/
    - https://github.com/fox-it/LDAPFragger
author: Huntrule Team
date: 2026-01-06
tags:
    - attack.t1001.003
    - attack.command-and-control
logsource:
    product: windows
    category: file_event
detection:
    selection:
        TargetFilename|contains: '\Local\Microsoft\Windows\SchCache\'
        TargetFilename|endswith: '.sch'
    filter_main_generic:
        - Image|endswith:
              - ':\Program Files\Cylance\Desktop\CylanceSvc.exe'
              - ':\Windows\CCM\CcmExec.exe'
              - ':\windows\system32\dllhost.exe'
              - ':\Windows\system32\dsac.exe'
              - ':\Windows\system32\efsui.exe'
              - ':\windows\system32\mmc.exe'
              - ':\windows\system32\svchost.exe'
              - ':\Windows\System32\wbem\WmiPrvSE.exe'
              - ':\windows\system32\WindowsPowerShell\v1.0\powershell.exe'
        - Image|contains:
              - ':\Windows\ccmsetup\autoupgrade\ccmsetup'
              - ':\Program Files\SentinelOne\Sentinel Agent'
    filter_main_office:
        Image|contains|all:
            - ':\Program Files\'
            - '\Microsoft Office'
        Image|endswith: '\OUTLOOK.EXE'
    filter_optional_ldapwhoami:
        Image|endswith: '\LANDesk\LDCLient\ldapwhoami.exe'
    filter_optional_citrix:
        Image|endswith: ':\Program Files\Citrix\Receiver StoreFront\Services\DefaultDomainServices\Citrix.DeliveryServices.DomainServices.ServiceHost.exe'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: medium

Known false positives

  • Unknown

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.