rule win_kurton_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.kurton."
        info = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.6.0"
        signator_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.kurton"
        malpedia_rule_date = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        malpedia_license = "CC BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    /* DISCLAIMER
     * The strings used in this rule have been automatically selected from the
     * disassembly of memory dumps and unpacked files, using YARA-Signator.
     * The code and documentation is published here:
     * https://github.com/fxb-cocacoding/yara-signator
     * As Malpedia is used as data source, please note that for a given
     * number of families, only single samples are documented.
     * This likely impacts the degree of generalization these rules will offer.
     * Take the described generation method also into consideration when you
     * apply the rules in your use cases and assign them confidence levels.
     */


    strings:
        $sequence_0 = { 8d9424ac040000 51 52 50 }
            // n = 4, score = 100
            //   8d9424ac040000       | lea                 edx, [esp + 0x4ac]
            //   51                   | push                ecx
            //   52                   | push                edx
            //   50                   | push                eax

        $sequence_1 = { 55 68e8030000 ff15???????? 8b467c 8b2d???????? 53 50 }
            // n = 7, score = 100
            //   55                   | push                ebp
            //   68e8030000           | push                0x3e8
            //   ff15????????         |                     
            //   8b467c               | mov                 eax, dword ptr [esi + 0x7c]
            //   8b2d????????         |                     
            //   53                   | push                ebx
            //   50                   | push                eax

        $sequence_2 = { 8bc6 83e61f c1f805 59 8b0485a05b0210 8d0cf6 8064880400 }
            // n = 7, score = 100
            //   8bc6                 | mov                 eax, esi
            //   83e61f               | and                 esi, 0x1f
            //   c1f805               | sar                 eax, 5
            //   59                   | pop                 ecx
            //   8b0485a05b0210       | mov                 eax, dword ptr [eax*4 + 0x10025ba0]
            //   8d0cf6               | lea                 ecx, [esi + esi*8]
            //   8064880400           | and                 byte ptr [eax + ecx*4 + 4], 0

        $sequence_3 = { 33c0 c1e902 f3a5 8bca 8d5570 83e103 f3a4 }
            // n = 7, score = 100
            //   33c0                 | xor                 eax, eax
            //   c1e902               | shr                 ecx, 2
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   8bca                 | mov                 ecx, edx
            //   8d5570               | lea                 edx, [ebp + 0x70]
            //   83e103               | and                 ecx, 3
            //   f3a4                 | rep movsb           byte ptr es:[edi], byte ptr [esi]

        $sequence_4 = { 894508 8bc6 c1f805 8d1c85a05b0210 8bc6 83e01f }
            // n = 6, score = 100
            //   894508               | mov                 dword ptr [ebp + 8], eax
            //   8bc6                 | mov                 eax, esi
            //   c1f805               | sar                 eax, 5
            //   8d1c85a05b0210       | lea                 ebx, [eax*4 + 0x10025ba0]
            //   8bc6                 | mov                 eax, esi
            //   83e01f               | and                 eax, 0x1f

        $sequence_5 = { 8d4c242c 50 57 e8???????? 68???????? e8???????? 83c404 }
            // n = 7, score = 100
            //   8d4c242c             | lea                 ecx, [esp + 0x2c]
            //   50                   | push                eax
            //   57                   | push                edi
            //   e8????????           |                     
            //   68????????           |                     
            //   e8????????           |                     
            //   83c404               | add                 esp, 4

        $sequence_6 = { 668b886aca0110 894a78 33c9 668b8868ca0110 898a84000000 33c9 }
            // n = 6, score = 100
            //   668b886aca0110       | mov                 cx, word ptr [eax + 0x1001ca6a]
            //   894a78               | mov                 dword ptr [edx + 0x78], ecx
            //   33c9                 | xor                 ecx, ecx
            //   668b8868ca0110       | mov                 cx, word ptr [eax + 0x1001ca68]
            //   898a84000000         | mov                 dword ptr [edx + 0x84], ecx
            //   33c9                 | xor                 ecx, ecx

        $sequence_7 = { 8b0c8da05b0210 f644810401 8d0481 7403 8b00 c3 e8???????? }
            // n = 7, score = 100
            //   8b0c8da05b0210       | mov                 ecx, dword ptr [ecx*4 + 0x10025ba0]
            //   f644810401           | test                byte ptr [ecx + eax*4 + 4], 1
            //   8d0481               | lea                 eax, [ecx + eax*4]
            //   7403                 | je                  5
            //   8b00                 | mov                 eax, dword ptr [eax]
            //   c3                   | ret                 
            //   e8????????           |                     

        $sequence_8 = { 7509 8b0c85802b0210 eb07 8b0c85b42b0210 }
            // n = 4, score = 100
            //   7509                 | jne                 0xb
            //   8b0c85802b0210       | mov                 ecx, dword ptr [eax*4 + 0x10022b80]
            //   eb07                 | jmp                 9
            //   8b0c85b42b0210       | mov                 ecx, dword ptr [eax*4 + 0x10022bb4]

        $sequence_9 = { 56 8bf1 57 8b8c24a8080000 68a20f0000 50 51 }
            // n = 7, score = 100
            //   56                   | push                esi
            //   8bf1                 | mov                 esi, ecx
            //   57                   | push                edi
            //   8b8c24a8080000       | mov                 ecx, dword ptr [esp + 0x8a8]
            //   68a20f0000           | push                0xfa2
            //   50                   | push                eax
            //   51                   | push                ecx

    condition:
        7 of them and filesize < 344064
}