rule win_kapeka_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.kapeka."
        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.kapeka"
        malpedia_rule_date = "20260916"
        malpedia_hash = "53a643781c18e08f4a50949af60172d837a0b6f6"
        malpedia_version = "20260917"
        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 = { 4c8bf2 488bf9 483bca 0f8415010000 4533c9 48895c2430 4533c0 }
            // n = 7, score = 100
            //   4c8bf2               | and                 edi, 0xfffffe00
            //   488bf9               | dec                 eax
            //   483bca               | mov                 dword ptr [ecx + 0x10], eax
            //   0f8415010000         | dec                 eax
            //   4533c9               | mov                 esi, edx
            //   48895c2430           | dec                 eax
            //   4533c0               | lea                 edi, [esi + 0x80]

        $sequence_1 = { 488d055dbc0100 48c7412000020000 488901 498db000020000 33c0 488bd9 48894108 }
            // n = 7, score = 100
            //   488d055dbc0100       | dec                 ecx
            //   48c7412000020000     | mov                 esi, eax
            //   488901               | inc                 esp
            //   498db000020000       | mov                 ecx, dword ptr [esp + 0x70]
            //   33c0                 | dec                 eax
            //   488bd9               | lea                 ecx, [esp + 0x38]
            //   48894108             | dec                 eax

        $sequence_2 = { 488d15065f0100 488bcf e8???????? 488bd6 488bc8 e8???????? 488d15245f0100 }
            // n = 7, score = 100
            //   488d15065f0100       | dec                 eax
            //   488bcf               | mov                 ecx, ebx
            //   e8????????           |                     
            //   488bd6               | dec                 eax
            //   488bc8               | mov                 edx, esi
            //   e8????????           |                     
            //   488d15245f0100       | dec                 eax

        $sequence_3 = { 488d542460 488d4dd0 e8???????? 488bcf e8???????? 488d4dd0 }
            // n = 6, score = 100
            //   488d542460           | mov                 dword ptr [esp + 0x30], ebx
            //   488d4dd0             | lea                 ecx, [ebx + 4]
            //   e8????????           |                     
            //   488bcf               | inc                 ecx
            //   e8????????           |                     
            //   488d4dd0             | mov                 eax, 0x820

        $sequence_4 = { 4889742430 488b5010 4885d2 7422 0f1f8000000000 488911 488bc8 }
            // n = 7, score = 100
            //   4889742430           | dec                 eax
            //   488b5010             | sub                 dword ptr [esp + 0x48], 2
            //   4885d2               | dec                 eax
            //   7422                 | mov                 ecx, dword ptr [esp + 0x78]
            //   0f1f8000000000       | dec                 esp
            //   488911               | mov                 esi, eax
            //   488bc8               | dec                 eax

        $sequence_5 = { 745f 498bcc e8???????? 488d4dd0 488bd8 e8???????? }
            // n = 6, score = 100
            //   745f                 | mov                 dword ptr [ebp - 8], 0x144
            //   498bcc               | inc                 esp
            //   e8????????           |                     
            //   488d4dd0             | mov                 byte ptr [ebp - 4], bh
            //   488bd8               | dec                 eax
            //   e8????????           |                     

        $sequence_6 = { 7409 488bce ff15???????? 41b804000000 488d5567 488bcb e8???????? }
            // n = 7, score = 100
            //   7409                 | lea                 ecx, [edi + 0x18]
            //   488bce               | mov                 edx, 2
            //   ff15????????         |                     
            //   41b804000000         | dec                 eax
            //   488d5567             | lea                 ecx, [ebp + 0x160]
            //   488bcb               | dec                 esp
            //   e8????????           |                     

        $sequence_7 = { 4c8b07 498b4020 492b4018 4883f80a 7d10 ba05000000 498bc8 }
            // n = 7, score = 100
            //   4c8b07               | mov                 edx, edi
            //   498b4020             | dec                 eax
            //   492b4018             | lea                 edi, [ebp - 8]
            //   4883f80a             | mov                 ecx, 0x18
            //   7d10                 | mov                 dword ptr [ebp + 0x40], 0x68
            //   ba05000000           | rep stosb           byte ptr es:[edi], al
            //   498bc8               | inc                 ebp

        $sequence_8 = { 4885c0 0f8591000000 48896c2430 4889742438 ff15???????? 4c8bc7 }
            // n = 6, score = 100
            //   4885c0               | and                 edi, 0xfffffe00
            //   0f8591000000         | dec                 eax
            //   48896c2430           | mov                 dword ptr [ecx + 0x10], eax
            //   4889742438           | dec                 eax
            //   ff15????????         |                     
            //   4c8bc7               | mov                 esi, edx

        $sequence_9 = { 75da 41f7d0 41b9fbffffff 49ba0d00008002000080 453bc1 732a }
            // n = 6, score = 100
            //   75da                 | mov                 dword ptr [ebp - 0x19], ecx
            //   41f7d0               | jmp                 0x1c6
            //   41b9fbffffff         | movups              xmm0, xmmword ptr [ebp - 0x19]
            //   49ba0d00008002000080     | movups    xmmword ptr [ebp - 0x29], xmm0
            //   453bc1               | jae                 0x1fb
            //   732a                 | dec                 eax

    condition:
        7 of them and filesize < 377856
}