title: Suspicious Workstation Locking via Rundll32
id: 3b5b0213-0460-4e3f-8937-3abf98ff7dcc
status: test
description: Detects a suspicious call to the user32.dll function that locks the user workstation
references:
    - https://app.any.run/tasks/2aef9c63-f944-4763-b3ef-81eee209d128/
author: frack113
date: 2022-06-04
modified: 2023-02-09
tags:
    - attack.stealth
logsource:
    category: process_creation
    product: windows
detection:
    selection_call_img:
        - Image|endswith: '\rundll32.exe'
        - OriginalFileName: 'RUNDLL32.EXE'
    selection_call_parent:
        ParentImage|endswith: '\cmd.exe'
    selection_call_cli:
        CommandLine|contains: 'user32.dll,'
    selection_function:
        CommandLine|contains: 'LockWorkStation'
    condition: all of selection_*
falsepositives:
    - Scripts or links on the user desktop used to lock the workstation instead of Windows+L or the menu option
level: medium

title: Locked Workstation
id: 411742ad-89b0-49cb-a7b0-3971b5c1e0a4
status: stable
description: Detects locked workstation session events that occur automatically after a standard period of inactivity.
references:
    - https://www.cisecurity.org/controls/cis-controls-list/
    - https://www.pcisecuritystandards.org/documents/PCI_DSS_v3-2-1.pdf
    - https://nvlpubs.nist.gov/nistpubs/CSWP/NIST.CSWP.04162018.pdf
    - https://www.ultimatewindowssecurity.com/securitylog/encyclopedia/event.aspx?eventID=4800
author: Alexandr Yampolskyi, SOC Prime
date: 2019-03-26
modified: 2023-12-11
tags:
    - attack.impact
    # - CSC16
    # - CSC16.11
    # - ISO27002-2013 A.9.1.1
    # - ISO27002-2013 A.9.2.1
    # - ISO27002-2013 A.9.2.2
    # - ISO27002-2013 A.9.2.3
    # - ISO27002-2013 A.9.2.4
    # - ISO27002-2013 A.9.2.5
    # - ISO27002-2013 A.9.2.6
    # - ISO27002-2013 A.9.3.1
    # - ISO27002-2013 A.9.4.1
    # - ISO27002-2013 A.9.4.3
    # - ISO27002-2013 A.11.2.8
    # - PCI DSS 3.1 7.1
    # - PCI DSS 3.1 7.2
    # - PCI DSS 3.1 7.3
    # - PCI DSS 3.1 8.7
    # - PCI DSS 3.1 8.8
    # - NIST CSF 1.1 PR.AC-1
    # - NIST CSF 1.1 PR.AC-4
    # - NIST CSF 1.1 PR.AC-6
    # - NIST CSF 1.1 PR.AC-7
    # - NIST CSF 1.1 PR.PT-3
logsource:
    product: windows
    service: security
detection:
    selection:
        EventID: 4800
    condition: selection
falsepositives:
    - Likely
level: informational

title: UAC Bypass Using Windows Media Player - File
id: 68578b43-65df-4f81-9a9b-92f32711a951
status: test
description: Detects the pattern of UAC Bypass using Windows Media Player osksupport.dll (UACMe 32)
references:
    - https://github.com/hfiref0x/UACME
author: Christian Burkard (Nextron Systems)
date: 2021-08-23
modified: 2022-10-09
tags:
    - attack.privilege-escalation
    - attack.t1548.002
logsource:
    category: file_event
    product: windows
detection:
    selection1:
        TargetFilename|startswith: 'C:\Users\'
        TargetFilename|endswith: '\AppData\Local\Temp\OskSupport.dll'
    selection2:
        Image: 'C:\Windows\system32\DllHost.exe'
        TargetFilename: 'C:\Program Files\Windows Media Player\osk.exe'
    condition: 1 of selection*
falsepositives:
    - Unknown
level: high

title: UAC Bypass Using Windows Media Player - Process
id: 0058b9e5-bcd7-40d4-9205-95ca5a16d7b2
status: test
description: Detects the pattern of UAC Bypass using Windows Media Player osksupport.dll (UACMe 32)
references:
    - https://github.com/hfiref0x/UACME
author: Christian Burkard (Nextron Systems)
date: 2021-08-23
modified: 2024-12-01
tags:
    - attack.privilege-escalation
    - attack.t1548.002
logsource:
    category: process_creation
    product: windows
detection:
    selection_img_1:
        Image: 'C:\Program Files\Windows Media Player\osk.exe'
    selection_img_2:
        Image: 'C:\Windows\System32\cmd.exe'
        ParentCommandLine: '"C:\Windows\system32\mmc.exe" "C:\Windows\system32\eventvwr.msc" /s'
    selection_integrity:
        IntegrityLevel:
            - 'High'
            - 'System'
            - 'S-1-16-16384' # System
            - 'S-1-16-12288' # High
    condition: 1 of selection_img_* and selection_integrity
falsepositives:
    - Unknown
level: high

title: UAC Bypass Using Windows Media Player - Registry
id: 5f9db380-ea57-4d1e-beab-8a2d33397e93
status: test
description: Detects the pattern of UAC Bypass using Windows Media Player osksupport.dll (UACMe 32)
references:
    - https://github.com/hfiref0x/UACME
author: Christian Burkard (Nextron Systems)
date: 2021-08-23
modified: 2023-08-17
tags:
    - attack.privilege-escalation
    - attack.t1548.002
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|endswith: '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Compatibility Assistant\Store\C:\Program Files\Windows Media Player\osk.exe'
        Details: 'Binary Data'
    condition: selection
falsepositives:
    - Unknown
level: high

title: Flash Player Update from Suspicious Location
id: 4922a5dd-6743-4fc2-8e81-144374280997
status: test
description: Detects a flashplayer update from an unofficial location
references:
    - https://gist.github.com/roycewilliams/a723aaf8a6ac3ba4f817847610935cfb
author: Florian Roth (Nextron Systems)
date: 2017-10-25
modified: 2022-08-08
tags:
    - attack.initial-access
    - attack.stealth
    - attack.t1189
    - attack.execution
    - attack.t1204.002
    - attack.t1036.005
logsource:
    category: proxy
detection:
    selection:
        - c-uri|contains: '/flash_install.php'
        - c-uri|endswith: '/install_flash_player.exe'
    filter:
        cs-host|endswith: '.adobe.com'
    condition: selection and not filter
falsepositives:
    - Unknown flash download locations
level: high