rule win_kuaibu8_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.kuaibu8."
        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.kuaibu8"
        malpedia_rule_date = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        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 = { 7404 3c5c 7503 c60100 8d8c2410010000 51 e8???????? }
            // n = 7, score = 100
            //   7404                 | je                  6
            //   3c5c                 | cmp                 al, 0x5c
            //   7503                 | jne                 5
            //   c60100               | mov                 byte ptr [ecx], 0
            //   8d8c2410010000       | lea                 ecx, [esp + 0x110]
            //   51                   | push                ecx
            //   e8????????           |                     

        $sequence_1 = { 8b9698160000 8b4c2414 42 899698160000 81e1ff000000 33d2 8a91e08b4300 }
            // n = 7, score = 100
            //   8b9698160000         | mov                 edx, dword ptr [esi + 0x1698]
            //   8b4c2414             | mov                 ecx, dword ptr [esp + 0x14]
            //   42                   | inc                 edx
            //   899698160000         | mov                 dword ptr [esi + 0x1698], edx
            //   81e1ff000000         | and                 ecx, 0xff
            //   33d2                 | xor                 edx, edx
            //   8a91e08b4300         | mov                 dl, byte ptr [ecx + 0x438be0]

        $sequence_2 = { 5b 81c440030000 c21000 3b7810 7d09 50 e8???????? }
            // n = 7, score = 100
            //   5b                   | pop                 ebx
            //   81c440030000         | add                 esp, 0x340
            //   c21000               | ret                 0x10
            //   3b7810               | cmp                 edi, dword ptr [eax + 0x10]
            //   7d09                 | jge                 0xb
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_3 = { 83c404 e9???????? 8965f0 ff75fc ff15???????? 90 90 }
            // n = 7, score = 100
            //   83c404               | add                 esp, 4
            //   e9????????           |                     
            //   8965f0               | mov                 dword ptr [ebp - 0x10], esp
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   ff15????????         |                     
            //   90                   | nop                 
            //   90                   | nop                 

        $sequence_4 = { 8945ec 6804000080 6a00 68???????? 6804000080 6a00 a1???????? }
            // n = 7, score = 100
            //   8945ec               | mov                 dword ptr [ebp - 0x14], eax
            //   6804000080           | push                0x80000004
            //   6a00                 | push                0
            //   68????????           |                     
            //   6804000080           | push                0x80000004
            //   6a00                 | push                0
            //   a1????????           |                     

        $sequence_5 = { 50 56 e8???????? 5e 81c40c010000 c3 b8fdffffff }
            // n = 7, score = 100
            //   50                   | push                eax
            //   56                   | push                esi
            //   e8????????           |                     
            //   5e                   | pop                 esi
            //   81c40c010000         | add                 esp, 0x10c
            //   c3                   | ret                 
            //   b8fdffffff           | mov                 eax, 0xfffffffd

        $sequence_6 = { 51 c1e810 50 899524010000 e8???????? 83c408 }
            // n = 6, score = 100
            //   51                   | push                ecx
            //   c1e810               | shr                 eax, 0x10
            //   50                   | push                eax
            //   899524010000         | mov                 dword ptr [ebp + 0x124], edx
            //   e8????????           |                     
            //   83c408               | add                 esp, 8

        $sequence_7 = { 0f8406000000 8bca 33c0 f3ab ff75fc e8???????? 83c404 }
            // n = 7, score = 100
            //   0f8406000000         | je                  0xc
            //   8bca                 | mov                 ecx, edx
            //   33c0                 | xor                 eax, eax
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   e8????????           |                     
            //   83c404               | add                 esp, 4

        $sequence_8 = { 8d942454020000 68???????? 52 e8???????? 8d44242c 50 6a00 }
            // n = 7, score = 100
            //   8d942454020000       | lea                 edx, [esp + 0x254]
            //   68????????           |                     
            //   52                   | push                edx
            //   e8????????           |                     
            //   8d44242c             | lea                 eax, [esp + 0x2c]
            //   50                   | push                eax
            //   6a00                 | push                0

        $sequence_9 = { 33d2 8a90e08a4300 8bc2 66ff848680090000 8b8694160000 8b8e98160000 }
            // n = 6, score = 100
            //   33d2                 | xor                 edx, edx
            //   8a90e08a4300         | mov                 dl, byte ptr [eax + 0x438ae0]
            //   8bc2                 | mov                 eax, edx
            //   66ff848680090000     | inc                 word ptr [esi + eax*4 + 0x980]
            //   8b8694160000         | mov                 eax, dword ptr [esi + 0x1694]
            //   8b8e98160000         | mov                 ecx, dword ptr [esi + 0x1698]

    condition:
        7 of them and filesize < 737280
}