CoCalc provides the best real-time collaborative environment for Jupyter Notebooks, LaTeX documents, and SageMath, scalable from individual users to large groups and classes!

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##
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# This module requires Metasploit: https://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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class MetasploitModule < Msf::Encoder::XorAdditiveFeedback
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  # Uncomment when we get the poly stuff working again.
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  #Rank = GreatRanking
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  def initialize
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    super(
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      'Name'             => 'Jump/Call XOR Additive Feedback Encoder',
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      'Description'      => 'Jump/Call XOR Additive Feedback',
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      'Author'           => 'skape',
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      'Arch'             => ARCH_X86,
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      'License'          => MSF_LICENSE,
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      'Decoder'          =>
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        {
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          'Stub'       =>
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            "\xfc"                + # cld
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            "\xbbXORK"            + # mov ebx, key
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            "\xeb\x0c"            + # jmp short 0x14
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            "\x5e"                + # pop esi
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            "\x56"                + # push esi
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            "\x31\x1e"            + # xor [esi], ebx
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            "\xad"                + # lodsd
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            "\x01\xc3"            + # add ebx, eax
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            "\x85\xc0"            + # test eax, eax
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            "\x75\xf7"            + # jnz 0xa
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            "\xc3"                + # ret
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            "\xe8\xef\xff\xff\xff", # call 0x8
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          'KeyOffset' => 2,
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          'KeySize'   => 4,
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          'BlockSize' => 4,
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        })
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  end
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  #
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  # Append the termination block.
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  #
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  def encode_end(state)
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    state.encoded += [ state.key ].pack(state.decoder_key_pack)
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  end
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end
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