52 lines
1.5 KiB
YAML
52 lines
1.5 KiB
YAML
title: Suspicious Double Extension
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author: Florian Roth (rule), @blu3_team (idea)
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date: 2019/06/26
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description: Detects suspicious use of an .exe extension after a non-executable file
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extension like .pdf.exe, a set of spaces or underlines to cloak the executable
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file in spear phishing campaigns
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detection:
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SELECTION_1:
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EventID: 1
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SELECTION_10:
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Image: '*.txt.exe'
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SELECTION_11:
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Image: '* .exe'
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SELECTION_12:
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Image: '*______.exe'
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SELECTION_2:
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Image: '*.doc.exe'
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SELECTION_3:
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Image: '*.docx.exe'
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SELECTION_4:
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Image: '*.xls.exe'
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SELECTION_5:
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Image: '*.xlsx.exe'
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SELECTION_6:
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Image: '*.ppt.exe'
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SELECTION_7:
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Image: '*.pptx.exe'
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SELECTION_8:
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Image: '*.rtf.exe'
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SELECTION_9:
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Image: '*.pdf.exe'
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condition: (SELECTION_1 and (SELECTION_2 or SELECTION_3 or SELECTION_4 or SELECTION_5
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or SELECTION_6 or SELECTION_7 or SELECTION_8 or SELECTION_9 or SELECTION_10
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or SELECTION_11 or SELECTION_12))
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falsepositives:
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- Unknown
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id: 1cdd9a09-06c9-4769-99ff-626e2b3991b8
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level: critical
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logsource:
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category: process_creation
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product: windows
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references:
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- https://blu3-team.blogspot.com/2019/06/misleading-extensions-xlsexe-docexe.html
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- https://twitter.com/blackorbird/status/1140519090961825792
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tags:
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- attack.initial_access
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- attack.t1566.001
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- attack.t1193
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yml_filename: win_susp_double_extension.yml
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yml_path: /Users/user/Documents/YamatoSecurity/sigma/rules/windows/process_creation
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