title: HTTP Logging Disabled On IIS Server
id: e8ebd53a-30c2-45bd-81bb-74befba07bdb
status: test
description: Detects changes to of the IIS server configuration in order to disable HTTP logging for successful requests.
references:
    - https://learn.microsoft.com/en-us/iis/manage/provisioning-and-managing-iis/configure-logging-in-iis
    - https://www.microsoft.com/en-us/security/blog/2022/12/12/iis-modules-the-evolution-of-web-shells-and-how-to-detect-them/
    - https://learn.microsoft.com/en-us/iis/configuration/system.webserver/httplogging
author: frack113
date: 2024-10-06
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1685.001
    - attack.t1505.004
logsource:
    product: windows
    service: iis-configuration
detection:
    selection:
        EventID: 29
        Configuration: '/system.webServer/httpLogging/@dontLog'
        NewValue: 'true'
    condition: selection
falsepositives:
    - Unknown
level: high

title: Suspicious IIS Module Registration
id: 043c4b8b-3a54-4780-9682-081cb6b8185c
status: test
description: Detects a suspicious IIS module registration as described in Microsoft threat report on IIS backdoors
references:
    - https://www.microsoft.com/security/blog/2022/07/26/malicious-iis-extensions-quietly-open-persistent-backdoors-into-servers/
author: Florian Roth (Nextron Systems), Microsoft (idea)
date: 2022-08-04
modified: 2023-01-23
tags:
    - attack.persistence
    - attack.t1505.004
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        ParentImage|endswith: '\w3wp.exe'
    selection_cli_1:
        CommandLine|contains: 'appcmd.exe add module'
    selection_cli_2:
        CommandLine|contains: ' system.enterpriseservices.internal.publish'
        Image|endswith: '\powershell.exe'
    selection_cli_3:
        CommandLine|contains|all:
            - 'gacutil'
            - ' /I'
    condition: selection_parent and 1 of selection_cli_*
falsepositives:
    - Administrative activity
level: high

title: ETW Logging/Processing Option Disabled On IIS Server
id: a5b40a90-baf5-4bf7-a6f7-373494881d22
status: test
description: Detects changes to of the IIS server configuration in order to disable/remove the ETW logging/processing option.
references:
    - https://learn.microsoft.com/en-us/iis/manage/provisioning-and-managing-iis/configure-logging-in-iis
    - https://www.microsoft.com/en-us/security/blog/2022/12/12/iis-modules-the-evolution-of-web-shells-and-how-to-detect-them/
    - https://learn.microsoft.com/en-us/iis/configuration/system.applicationhost/sites/sitedefaults/logfile/
author: frack113, Nasreddine Bencherchali
date: 2024-10-06
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1685.001
    - attack.t1505.004
logsource:
    product: windows
    service: iis-configuration
detection:
    selection:
        EventID: 29
        Configuration|endswith: '@logTargetW3C'
        OldValue|contains: 'ETW'
    filter_main_etw_added:
        NewValue|contains: 'ETW'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate administrator activity
level: medium

title: New Module Module Added To IIS Server
id: dd857d3e-0c6e-457b-9b48-e82ae7f86bd7
status: test
description: Detects the addition of a new module to an IIS server.
references:
    - https://learn.microsoft.com/en-us/iis/manage/provisioning-and-managing-iis/configure-logging-in-iis
    - https://www.microsoft.com/en-us/security/blog/2022/12/12/iis-modules-the-evolution-of-web-shells-and-how-to-detect-them/
    - https://www.microsoft.com/en-us/security/blog/2022/07/26/malicious-iis-extensions-quietly-open-persistent-backdoors-into-servers/
    - https://learn.microsoft.com/en-us/iis/get-started/introduction-to-iis/iis-modules-overview
author: frack113
date: 2024-10-06
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1685.001
    - attack.t1505.004
logsource:
    product: windows
    service: iis-configuration
detection:
    selection:
        EventID: 29
        Configuration|contains: '/system.webServer/modules/add'
    filter_main_builtin:
        NewValue:
            - 'AnonymousAuthenticationModule'
            - 'CustomErrorModule'
            - 'DefaultDocumentModule'
            - 'DirectoryListingModule'
            - 'FileCacheModule'
            - 'HttpCacheModule'
            - 'HttpLoggingModule'
            - 'ProtocolSupportModule'
            - 'RequestFilteringModule'
            - 'StaticCompressionModule'
            - 'StaticFileModule'
            - 'TokenCacheModule'
            - 'UriCacheModule'
    filter_main_remove:
        NewValue: ''
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate administrator activity
level: medium

title: Previously Installed IIS Module Was Removed
id: 9e1a1fdf-ee58-40ce-8e15-b66ca5a80e1f
status: test
description: Detects the removal of a previously installed IIS module.
references:
    - https://learn.microsoft.com/en-us/iis/manage/provisioning-and-managing-iis/configure-logging-in-iis
    - https://www.microsoft.com/en-us/security/blog/2022/12/12/iis-modules-the-evolution-of-web-shells-and-how-to-detect-them/
    - https://www.microsoft.com/en-us/security/blog/2022/07/26/malicious-iis-extensions-quietly-open-persistent-backdoors-into-servers/
    - https://learn.microsoft.com/en-us/iis/get-started/introduction-to-iis/iis-modules-overview
author: Nasreddine Bencherchali
date: 2024-10-06
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1685.001
    - attack.t1505.004
logsource:
    product: windows
    service: iis-configuration
detection:
    selection:
        EventID: 29
        Configuration|contains: '/system.webServer/modules/remove'
    condition: selection
falsepositives:
    - Legitimate administrator activity
# Note: Upgrade after an initial baseline
level: low