24 lines
841 B
Text
24 lines
841 B
Text
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/*
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Yara Rule Set
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Author: YarGen Rule Generator
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Date: 2016-05-21
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Identifier: No PowerShell
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*/
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rule No_PowerShell {
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meta:
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description = "Detects an C# executable used to circumvent PowerShell detection - file nps.exe"
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license = "Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE"
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author = "Florian Roth (Nextron Systems)"
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reference = "https://github.com/Ben0xA/nps"
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date = "2016-05-21"
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score = 80
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hash1 = "64f811b99eb4ae038c88c67ee0dc9b150445e68a2eb35ff1a0296533ae2edd71"
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id = "362a61bc-2c10-5076-93be-9f8b5a9ae8ba"
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strings:
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$s1 = "nps.exe -encodedcommand {base64_encoded_command}" fullword wide
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$s2 = "c:\\Development\\ghps\\nps\\nps\\obj\\x86\\Release\\nps.pdb" fullword ascii
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condition:
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( uint16(0) == 0x5a4d and filesize < 40KB and ( 1 of ($s*) ) ) or ( all of them )
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}
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