rule win_kutaki_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.kutaki."
        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.kutaki"
        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 = { 8b8d50ffffff 51 ff502c dbe2 89854cffffff 83bd4cffffff00 7d23 }
            // n = 7, score = 700
            //   8b8d50ffffff         | mov                 ecx, dword ptr [ebp - 0xb0]
            //   51                   | push                ecx
            //   ff502c               | call                dword ptr [eax + 0x2c]
            //   dbe2                 | fnclex              
            //   89854cffffff         | mov                 dword ptr [ebp - 0xb4], eax
            //   83bd4cffffff00       | cmp                 dword ptr [ebp - 0xb4], 0
            //   7d23                 | jge                 0x25

        $sequence_1 = { 881401 c745fc0b000000 e9???????? c745fc0c000000 c745fc0d000000 8b45d8 8945c0 }
            // n = 7, score = 700
            //   881401               | mov                 byte ptr [ecx + eax], dl
            //   c745fc0b000000       | mov                 dword ptr [ebp - 4], 0xb
            //   e9????????           |                     
            //   c745fc0c000000       | mov                 dword ptr [ebp - 4], 0xc
            //   c745fc0d000000       | mov                 dword ptr [ebp - 4], 0xd
            //   8b45d8               | mov                 eax, dword ptr [ebp - 0x28]
            //   8945c0               | mov                 dword ptr [ebp - 0x40], eax

        $sequence_2 = { 83c40c 0fbf954cffffff 85d2 742c c745fc08000000 66c745dc0000 c745fc09000000 }
            // n = 7, score = 700
            //   83c40c               | add                 esp, 0xc
            //   0fbf954cffffff       | movsx               edx, word ptr [ebp - 0xb4]
            //   85d2                 | test                edx, edx
            //   742c                 | je                  0x2e
            //   c745fc08000000       | mov                 dword ptr [ebp - 4], 8
            //   66c745dc0000         | mov                 word ptr [ebp - 0x24], 0
            //   c745fc09000000       | mov                 dword ptr [ebp - 4], 9

        $sequence_3 = { 50 8b4da0 51 ff15???????? 898518ffffff eb0a c78518ffffff00000000 }
            // n = 7, score = 700
            //   50                   | push                eax
            //   8b4da0               | mov                 ecx, dword ptr [ebp - 0x60]
            //   51                   | push                ecx
            //   ff15????????         |                     
            //   898518ffffff         | mov                 dword ptr [ebp - 0xe8], eax
            //   eb0a                 | jmp                 0xc
            //   c78518ffffff00000000     | mov    dword ptr [ebp - 0xe8], 0

        $sequence_4 = { ff15???????? 8985a8feffff eb0a c785a8feffff00000000 8d4d90 ff15???????? 8d8550ffffff }
            // n = 7, score = 700
            //   ff15????????         |                     
            //   8985a8feffff         | mov                 dword ptr [ebp - 0x158], eax
            //   eb0a                 | jmp                 0xc
            //   c785a8feffff00000000     | mov    dword ptr [ebp - 0x158], 0
            //   8d4d90               | lea                 ecx, [ebp - 0x70]
            //   ff15????????         |                     
            //   8d8550ffffff         | lea                 eax, [ebp - 0xb0]

        $sequence_5 = { ff15???????? 898508feffff 8b9568ffffff 8b420c 8b8d08feffff 8b1408 8d4d94 }
            // n = 7, score = 700
            //   ff15????????         |                     
            //   898508feffff         | mov                 dword ptr [ebp - 0x1f8], eax
            //   8b9568ffffff         | mov                 edx, dword ptr [ebp - 0x98]
            //   8b420c               | mov                 eax, dword ptr [edx + 0xc]
            //   8b8d08feffff         | mov                 ecx, dword ptr [ebp - 0x1f8]
            //   8b1408               | mov                 edx, dword ptr [eax + ecx]
            //   8d4d94               | lea                 ecx, [ebp - 0x6c]

        $sequence_6 = { ff15???????? 8d55dc 899544ffffff eb09 8d45dc 898544ffffff 8b8d44ffffff }
            // n = 7, score = 700
            //   ff15????????         |                     
            //   8d55dc               | lea                 edx, [ebp - 0x24]
            //   899544ffffff         | mov                 dword ptr [ebp - 0xbc], edx
            //   eb09                 | jmp                 0xb
            //   8d45dc               | lea                 eax, [ebp - 0x24]
            //   898544ffffff         | mov                 dword ptr [ebp - 0xbc], eax
            //   8b8d44ffffff         | mov                 ecx, dword ptr [ebp - 0xbc]

        $sequence_7 = { 8b9588feffff c1e202 89950cfeffff eb0c ff15???????? 89850cfeffff 8b4508 }
            // n = 7, score = 700
            //   8b9588feffff         | mov                 edx, dword ptr [ebp - 0x178]
            //   c1e202               | shl                 edx, 2
            //   89950cfeffff         | mov                 dword ptr [ebp - 0x1f4], edx
            //   eb0c                 | jmp                 0xe
            //   ff15????????         |                     
            //   89850cfeffff         | mov                 dword ptr [ebp - 0x1f4], eax
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]

        $sequence_8 = { 6880000000 ff15???????? 83c41c c745fc06000000 c745fc07000000 8b4508 8b08 }
            // n = 7, score = 700
            //   6880000000           | push                0x80
            //   ff15????????         |                     
            //   83c41c               | add                 esp, 0x1c
            //   c745fc06000000       | mov                 dword ptr [ebp - 4], 6
            //   c745fc07000000       | mov                 dword ptr [ebp - 4], 7
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   8b08                 | mov                 ecx, dword ptr [eax]

        $sequence_9 = { ff15???????? 83c420 50 6a00 8d8568ffffff 50 }
            // n = 6, score = 700
            //   ff15????????         |                     
            //   83c420               | add                 esp, 0x20
            //   50                   | push                eax
            //   6a00                 | push                0
            //   8d8568ffffff         | lea                 eax, [ebp - 0x98]
            //   50                   | push                eax

    condition:
        7 of them and filesize < 1335296
}