rule win_kerrdown_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-10-14"
        version = "1"
        description = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.5.0"
        tool_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.kerrdown"
        malpedia_rule_date = "20201014"
        malpedia_hash = "a7e3bd57eaf12bf3ea29a863c041091ba3af9ac9"
        malpedia_version = "20201014"
        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 = { 6bc618 57 8db870ca3300 57 ff15???????? ff0d???????? 83ef18 }
            // n = 7, score = 100
            //   6bc618               | imul                eax, esi, 0x18
            //   57                   | push                edi
            //   8db870ca3300         | lea                 edi, [eax + 0x33ca70]
            //   57                   | push                edi
            //   ff15????????         |                     
            //   ff0d????????         |                     
            //   83ef18               | sub                 edi, 0x18

        $sequence_1 = { 8b1c8538083300 56 6800080000 6a00 53 }
            // n = 5, score = 100
            //   8b1c8538083300       | mov                 ebx, dword ptr [eax*4 + 0x330838]
            //   56                   | push                esi
            //   6800080000           | push                0x800
            //   6a00                 | push                0
            //   53                   | push                ebx

        $sequence_2 = { 8bec 8b4508 57 8d3c85c8cb3300 8b0f }
            // n = 5, score = 100
            //   8bec                 | mov                 ebp, esp
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   57                   | push                edi
            //   8d3c85c8cb3300       | lea                 edi, [eax*4 + 0x33cbc8]
            //   8b0f                 | mov                 ecx, dword ptr [edi]

        $sequence_3 = { 89882cc53300 68???????? e8???????? 8be5 }
            // n = 4, score = 100
            //   89882cc53300         | mov                 dword ptr [eax + 0x33c52c], ecx
            //   68????????           |                     
            //   e8????????           |                     
            //   8be5                 | mov                 esp, ebp

        $sequence_4 = { 0f8580000000 8b4508 dd00 ebc6 c745e078303300 e9???????? }
            // n = 6, score = 100
            //   0f8580000000         | jne                 0x86
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   dd00                 | fld                 qword ptr [eax]
            //   ebc6                 | jmp                 0xffffffc8
            //   c745e078303300       | mov                 dword ptr [ebp - 0x20], 0x333078
            //   e9????????           |                     

        $sequence_5 = { 7cef 33db 0f1f4000 8a441de8 }
            // n = 4, score = 100
            //   7cef                 | jl                  0xfffffff1
            //   33db                 | xor                 ebx, ebx
            //   0f1f4000             | nop                 dword ptr [eax]
            //   8a441de8             | mov                 al, byte ptr [ebp + ebx - 0x18]

        $sequence_6 = { 8b45dc 85c0 0f8544ffffff 85f6 0f848f000000 }
            // n = 5, score = 100
            //   8b45dc               | mov                 eax, dword ptr [ebp - 0x24]
            //   85c0                 | test                eax, eax
            //   0f8544ffffff         | jne                 0xffffff4a
            //   85f6                 | test                esi, esi
            //   0f848f000000         | je                  0x95

        $sequence_7 = { 57 50 e8???????? 83c40c 6b45e430 8945e0 8d8018513300 }
            // n = 7, score = 100
            //   57                   | push                edi
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   6b45e430             | imul                eax, dword ptr [ebp - 0x1c], 0x30
            //   8945e0               | mov                 dword ptr [ebp - 0x20], eax
            //   8d8018513300         | lea                 eax, [eax + 0x335118]

        $sequence_8 = { 660fd60f 8d7f08 8b048da42d3200 ffe0 f7c703000000 }
            // n = 5, score = 100
            //   660fd60f             | movq                qword ptr [edi], xmm1
            //   8d7f08               | lea                 edi, [edi + 8]
            //   8b048da42d3200       | mov                 eax, dword ptr [ecx*4 + 0x322da4]
            //   ffe0                 | jmp                 eax
            //   f7c703000000         | test                edi, 3

        $sequence_9 = { a4 7d15 6bcdac 73d0 }
            // n = 4, score = 100
            //   a4                   | movsb               byte ptr es:[edi], byte ptr [esi]
            //   7d15                 | jge                 0x17
            //   6bcdac               | imul                ecx, ebp, -0x54
            //   73d0                 | jae                 0xffffffd2

    condition:
        7 of them and filesize < 278528
}