title: Set OabVirtualDirectory ExternalUrl Property
id: 9db37458-4df2-46a5-95ab-307e7f29e675
description: Rule to detect an adversary setting OabVirtualDirectory External URL property to a script
author: Jose Rodriguez @Cyb3rPandaH
status: experimental
date: 2021/03/15
references:
    - https://twitter.com/OTR_Community/status/1371053369071132675
tags:
    - attack.persistence
    - attack.t1505.003
logsource:
    product: windows
    service: msexchange-management
detection:
    selection:
        Message|contains|all:
            - 'Set-OabVirtualDirectory'
            - 'ExternalUrl'
            - 'Page_Load'
            - 'script'
    condition: selection
falsepositives:
    - Unknown
level: high