yugoslavskiy
37 lines
1.6 KiB
YAML
37 lines
1.6 KiB
YAML
title: Invoke-Obfuscation obfuscated IEX invocation
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description: Detects all variations of obfuscated powershell IEX invocation code generated by Invoke-Obfuscation framework from the following code block — https://github.com/danielbohannon/Invoke-Obfuscation/blob/master/Out-ObfuscatedStringCommand.ps1#L873-L888
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status: experimental
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author: Daniel Bohannon (@Mandiant/@FireEye), oscd.community
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date: 2019/11/08
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tags:
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- attack.defense_evasion
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- attack.t1027
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logsource:
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product: windows
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service: powershell
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detection:
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selection_1:
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EventID: 4104
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selection_2:
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- ScriptBlockText|re: '\$PSHome\[\s*\d{1,3}\s*\]\s*\+\s*\$PSHome\['
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- ScriptBlockText|re: '\$ShellId\[\s*\d{1,3}\s*\]\s*\+\s*\$ShellId\['
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- ScriptBlockText|re: '\$env:Public\[\s*\d{1,3}\s*\]\s*\+\s*\$env:Public\['
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- ScriptBlockText|re: '\$env:ComSpec\[(\s*\d{1,3}\s*,){2}'
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- ScriptBlockText|re: '\*mdr\*\W\s*\)\.Name'
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- ScriptBlockText|re: '\$VerbosePreference\.ToString\('
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- ScriptBlockText|re: '\String\]\s*\$VerbosePreference'
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selection_3:
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EventID: 4103
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selection_4:
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- Payload|re: '\$PSHome\[\s*\d{1,3}\s*\]\s*\+\s*\$PSHome\['
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- Payload|re: '\$ShellId\[\s*\d{1,3}\s*\]\s*\+\s*\$ShellId\['
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- Payload|re: '\$env:Public\[\s*\d{1,3}\s*\]\s*\+\s*\$env:Public\['
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- Payload|re: '\$env:ComSpec\[(\s*\d{1,3}\s*,){2}'
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- Payload|re: '\*mdr\*\W\s*\)\.Name'
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- Payload|re: '\$VerbosePreference\.ToString\('
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- Payload|re: '\String\]\s*\$VerbosePreference'
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condition: ( selection_1 and selection_2 ) or ( selection_3 and selection_4 )
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falsepositives:
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- Unknown
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level: high
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