Detectionhightest
GAC DLL Loaded Via Office Applications
Detects any GAC DLL being loaded by an Office Product
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Log Source
WindowsImage Load (DLL)
ProductWindows← raw: windows
CategoryImage Load (DLL)← raw: image_load
Detection Logic
Detection Logic1 selector
detection:
selection:
Image|endswith:
- '\excel.exe'
- '\mspub.exe'
- '\onenote.exe'
- '\onenoteim.exe' # Just in case
- '\outlook.exe'
- '\powerpnt.exe'
- '\winword.exe'
ImageLoaded|startswith: 'C:\Windows\Microsoft.NET\assembly\GAC_MSIL'
condition: selectionFalse Positives
Legitimate macro usage. Add the appropriate filter according to your environment
References
MITRE ATT&CK
Tactics
Sub-techniques
Rule Metadata
Rule ID
90217a70-13fc-48e4-b3db-0d836c5824ac
Status
test
Level
high
Type
Detection
Created
Wed Feb 19
Modified
Fri Feb 10
Author
Path
rules/windows/image_load/image_load_office_dotnet_gac_dll_load.yml
Raw Tags
attack.executionattack.t1204.002