Potential Azure Browser SSO Abuse

Title: Potential Azure Browser SSO Abuse
Status: test
Description:Detects abusing Azure Browser SSO by requesting OAuth 2.0 refresh tokens for an Azure-AD-authenticated Windows user (i.e. the machine is joined to Azure AD and a user logs in with their Azure AD account) wanting to perform SSO authentication in the browser. An attacker can use this to authenticate to Azure AD in a browser as that user.
References:
  -https://posts.specterops.io/requesting-azure-ad-request-tokens-on-azure-ad-joined-machines-for-browser-sso-2b0409caad30
Author: Den Iuzvyk
Date: 2020-07-15
modified:2023-04-18
Tags:

• -'attack.persistence'
• -'attack.privilege-escalation'
• -'attack.execution'
• -'attack.stealth'
• -'attack.t1574.001'

Logsource:

• category: image_load
• product: windows

Detection:
  selection:
    ImageLoaded: 'C:\Windows\System32\MicrosoftAccountTokenProvider.dll'
  filter_main_bgtaskhost:
    Image|startswith:
      -'C:\Windows\System32\'
      -'C:\Windows\SysWOW64\'

    Image|endswith: '\BackgroundTaskHost.exe'
  filter_optional_devenv:
    Image|startswith:
      -'C:\Program Files\Microsoft Visual Studio\'
      -'C:\Program Files (x86)\Microsoft Visual Studio\'

    Image|endswith: '\IDE\devenv.exe'
  filter_optional_ie:
    Image:
      -'C:\Program Files (x86)\Internet Explorer\iexplore.exe'
      -'C:\Program Files\Internet Explorer\iexplore.exe'

  filter_optional_edge_1:
Image|startswith:'C:\Program Files (x86)\Microsoft\EdgeWebView\Application\' Image|endswith:'\WindowsApps\MicrosoftEdge.exe'     - Image:
      - 'C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe'
      - 'C:\Program Files\Microsoft\Edge\Application\msedge.exe'
  filter_optional_edge_2:
    Image|startswith:
      -'C:\Program Files (x86)\Microsoft\EdgeCore\'
      -'C:\Program Files\Microsoft\EdgeCore\'

    Image|endswith:
      -'\msedge.exe'
      -'\msedgewebview2.exe'

  filter_optional_onedrive:
    Image|endswith: '\AppData\Local\Microsoft\OneDrive\OneDrive.exe'
  filter_optional_null:
    Image: 'None'
  condition:selection and not 1 of filter_main_* and not 1 of filter_optional_*
Falsepositives:
  -False positives are expected since this rules is only looking for the DLL load event. This rule is better used in correlation with related activity
Level: low