Tim Shelton
42 lines
2.0 KiB
YAML
42 lines
2.0 KiB
YAML
title: Suspicious PowerShell Command Line
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id: d7bcd677-645d-4691-a8d4-7a5602b780d1
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status: test
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description: Detects the PowerShell command lines with special characters
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author: Teymur Kheirkhabarov (idea), Vasiliy Burov (rule), oscd.community, Tim Shelton (fp)
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references:
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- https://speakerdeck.com/heirhabarov/hunting-for-powershell-abuse?slide=64
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date: 2020/10/15
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modified: 2021/12/06
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logsource:
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category: process_creation
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product: windows
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detection:
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selection1:
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Image|endswith: '\powershell.exe'
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CommandLine|re: '.*\+.*\+.*\+.*\+.*\+.*\+.*\+.*\+.*\+.*\+.*\+.*\+.*\+.*\+.*'
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selection2:
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Image|endswith: '\powershell.exe'
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CommandLine|re: '.*\{.*\{.*\{.*\{.*\{.*\{.*\{.*\{.*\{.*\{.*'
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selection3:
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Image|endswith: '\powershell.exe'
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CommandLine|re: '.*{.*{.*{.*{.*{.*'
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selection4:
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Image|endswith: '\powershell.exe'
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CommandLine|re: '.*\^.*\^.*\^.*\^.*\^.*'
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selection5:
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Image|endswith: '\powershell.exe'
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CommandLine|re: '.*`.*`.*`.*`.*`.*'
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filter:
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ParentImage:
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- C:\Program Files\Amazon\SSM\ssm-document-worker.exe
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condition: (selection1 or selection2 or selection3 or selection4 or selection5) and not filter
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falsepositives:
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- Unlikely
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- Amazon SSM Document Worker # fp example: powershell " [Console]::OutputEncoding = [System.Text.Encoding]::UTF8 $keyExists = Test-Path "Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup\OC Manager\Subcomponents" $jsonObj = @() if ($keyExists) { $key = Get-Item "Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup\OC Manager\Subcomponents" $valueNames = $key.GetValueNames(); foreach ($valueName in $valueNames) { $value = $key.GetValue($valueName); if ($value -gt 0) { $installed = "True" } else { $installed = "False" } $jsonObj += @" {"Name": "$valueName", "Installed": "$installed"} "@ } } $result = $jsonObj -join "," $result = "[" + $result + "]" [Console]::WriteLine($result)
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level: high
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tags:
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- attack.defense_evasion
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- attack.t1027
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- attack.execution
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- attack.t1059.001
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