Detectionmediumtest

Suspicious File Drop by Exchange

Detects suspicious file type dropped by an Exchange component in IIS

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Launch
Florian Roth (Nextron Systems)Created Tue Oct 046b269392-9eba-40b5-acb6-55c882b20ba6windows
Log Source
WindowsFile Event
ProductWindows← raw: windows
CategoryFile Event← raw: file_event

Events for file system activity including creation, modification, and deletion.

Detection Logic
Detection Logic2 selectors
detection:
    selection:
        Image|endswith: '\w3wp.exe'
        CommandLine|contains: 'MSExchange'
    selection_types:
        TargetFilename|endswith:
            - '.aspx'
            - '.asp'
            - '.ashx'
            - '.ps1'
            - '.bat'
            - '.exe'
            - '.dll'
            - '.vbs'
    condition: all of selection*
False Positives
Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

Rule Metadata
Rule ID
6b269392-9eba-40b5-acb6-55c882b20ba6
Status
test
Level
medium
Type
Detection
Created
Tue Oct 04
Path
rules/windows/file/file_event/file_event_win_exchange_webshell_drop_suspicious.yml
Raw Tags
attack.persistenceattack.t1190attack.initial-accessattack.t1505.003
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