Suspicious Creation Of Non-Existent System DLL (via file_event)

title: Suspicious Creation Of Non-Existent System DLL (via file_event)
id: 83b2aa3c-7c20-53d0-b266-4cc3e27bf69f
status: stable
description: This rule detects creation of specific system DLL files that are usually not present on the system (or at least not in system directories) but may be loaded by legitimate processes. Phantom DLL hijacking involves placing hostile DLLs with names of non-existent system binaries in locations where legitimate applications may search for them, leading to execution of the hostile DLLs. Thus, the creation of such DLLs may indicate preparation for phantom DLL hijacking attacks.
references:
    - https://attack.mitre.org/techniques/T1574/001/
    - http://remoteawesomethoughts.blogspot.com/2019/05/windows-10-task-schedulerservice.html
    - https://clement.notin.org/blog/2020/09/12/CVE-2020-7315-McAfee-Agent-DLL-injection/
    - https://decoded.avast.io/martinchlumecky/png-steganography/
    - https://github.com/blackarrowsec/redteam-research/tree/26e6fc0c0d30d364758fa11c2922064a9a7fd309/LPE%20via%20StorSvc
    - https://github.com/Wh04m1001/SysmonEoP
    - https://itm4n.github.io/cdpsvc-dll-hijacking/
    - https://posts.specterops.io/lateral-movement-scm-and-dll-hijacking-primer-d2f61e8ab992
    - https://securelist.com/passiveneuron-campaign-with-apt-implants-and-cobalt-strike/117745/
    - https://www.crowdstrike.com/en-us/blog/4-ways-adversaries-hijack-dlls/
    - https://www.hexacorn.com/blog/2013/12/08/beyond-good-ol-run-key-part-5/
    - https://www.hexacorn.com/blog/2025/06/14/wermgr-exe-boot-offdmpsvc-dll-lolbin/
    - https://www.hexacorn.com/blog/2025/06/14/wpr-exe-boottrace-phantom-dll-axeonoffhelper-dll-lolbin/
    - https://x.com/0gtweet/status/1564131230941122561
author: Huntrule Team
date: 2026-07-24
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    product: windows
    category: file_event
detection:
    selection:
        TargetFilename|endswith:
            - ':\Windows\System32\axeonoffhelper.dll'
            - ':\Windows\System32\cdpsgshims.dll'
            - ':\Windows\System32\oci.dll'
            - ':\Windows\System32\offdmpsvc.dll'
            - ':\Windows\System32\shellchromeapi.dll'
            - ':\Windows\System32\TSMSISrv.dll'
            - ':\Windows\System32\TSVIPSrv.dll'
            - ':\Windows\System32\wbem\wbemcomn.dll'
            - ':\Windows\System32\WLBSCTRL.dll'
            - ':\Windows\System32\wow64log.dll'
            - ':\Windows\System32\WptsExtensions.dll'
            - '\SprintCSP.dll'
    condition: selection
falsepositives:
    - Unknown
level: medium
regression_tests_path: regression_data/rules/windows/file/file_event/file_event_win_create_non_existent_dlls/info.yml