rule win_kerrdown_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-08-05"
        version = "1"
        description = "Detects win.kerrdown."
        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.kerrdown"
        malpedia_rule_date = "20220805"
        malpedia_hash = "6ec06c64bcfdbeda64eff021c766b4ce34542b71"
        malpedia_version = "20220808"
        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 = { 03c2 3d???????? 762a ff750c 83ff10 ba???????? b8???????? }
            // n = 7, score = 200
            //   03c2                 | add                 eax, edx
            //   3d????????           |                     
            //   762a                 | jbe                 0x2c
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   83ff10               | cmp                 edi, 0x10
            //   ba????????           |                     
            //   b8????????           |                     

        $sequence_1 = { 57 8d7bff 8a4701 8d7f01 84c0 75f6 66a1???????? }
            // n = 7, score = 200
            //   57                   | push                edi
            //   8d7bff               | lea                 edi, [ebx - 1]
            //   8a4701               | mov                 al, byte ptr [edi + 1]
            //   8d7f01               | lea                 edi, [edi + 1]
            //   84c0                 | test                al, al
            //   75f6                 | jne                 0xfffffff8
            //   66a1????????         |                     

        $sequence_2 = { e8???????? 8bd8 83c408 8bd3 2bd6 8a0e }
            // n = 6, score = 200
            //   e8????????           |                     
            //   8bd8                 | mov                 ebx, eax
            //   83c408               | add                 esp, 8
            //   8bd3                 | mov                 edx, ebx
            //   2bd6                 | sub                 edx, esi
            //   8a0e                 | mov                 cl, byte ptr [esi]

        $sequence_3 = { 897ddc c745d800000000 33f6 c747140f000000 }
            // n = 4, score = 200
            //   897ddc               | mov                 dword ptr [ebp - 0x24], edi
            //   c745d800000000       | mov                 dword ptr [ebp - 0x28], 0
            //   33f6                 | xor                 esi, esi
            //   c747140f000000       | mov                 dword ptr [edi + 0x14], 0xf

        $sequence_4 = { 85f6 0f848f000000 33c0 83f804 }
            // n = 4, score = 200
            //   85f6                 | test                esi, esi
            //   0f848f000000         | je                  0x95
            //   33c0                 | xor                 eax, eax
            //   83f804               | cmp                 eax, 4

        $sequence_5 = { 3d???????? 773e 83ff10 b8???????? 0f43c1 }
            // n = 5, score = 200
            //   3d????????           |                     
            //   773e                 | ja                  0x40
            //   83ff10               | cmp                 edi, 0x10
            //   b8????????           |                     
            //   0f43c1               | cmovae              eax, ecx

        $sequence_6 = { f6c11f 752f 8b41fc 3bc1 732d 2bc8 }
            // n = 6, score = 200
            //   f6c11f               | test                cl, 0x1f
            //   752f                 | jne                 0x31
            //   8b41fc               | mov                 eax, dword ptr [ecx - 4]
            //   3bc1                 | cmp                 eax, ecx
            //   732d                 | jae                 0x2f
            //   2bc8                 | sub                 ecx, eax

        $sequence_7 = { 8b750c 83fefe 0f878d000000 3bfe 7366 }
            // n = 5, score = 200
            //   8b750c               | mov                 esi, dword ptr [ebp + 0xc]
            //   83fefe               | cmp                 esi, -2
            //   0f878d000000         | ja                  0x93
            //   3bfe                 | cmp                 edi, esi
            //   7366                 | jae                 0x68

        $sequence_8 = { 83fe03 7cec 8b4de0 33f6 8b45dc 85c0 0f8544ffffff }
            // n = 7, score = 200
            //   83fe03               | cmp                 esi, 3
            //   7cec                 | jl                  0xffffffee
            //   8b4de0               | mov                 ecx, dword ptr [ebp - 0x20]
            //   33f6                 | xor                 esi, esi
            //   8b45dc               | mov                 eax, dword ptr [ebp - 0x24]
            //   85c0                 | test                eax, eax
            //   0f8544ffffff         | jne                 0xffffff4a

        $sequence_9 = { 75f8 b90b000000 be???????? f3a5 68???????? }
            // n = 5, score = 200
            //   75f8                 | jne                 0xfffffffa
            //   b90b000000           | mov                 ecx, 0xb
            //   be????????           |                     
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   68????????           |                     

    condition:
        7 of them and filesize < 278528
}