rule win_xiaoba_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.xiaoba."
        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.xiaoba"
        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 = { 897e38 897e3c 66c746402a00 897e44 897e48 897e4c c7465064000000 }
            // n = 7, score = 100
            //   897e38               | mov                 dword ptr [esi + 0x38], edi
            //   897e3c               | mov                 dword ptr [esi + 0x3c], edi
            //   66c746402a00         | mov                 word ptr [esi + 0x40], 0x2a
            //   897e44               | mov                 dword ptr [esi + 0x44], edi
            //   897e48               | mov                 dword ptr [esi + 0x48], edi
            //   897e4c               | mov                 dword ptr [esi + 0x4c], edi
            //   c7465064000000       | mov                 dword ptr [esi + 0x50], 0x64

        $sequence_1 = { 0f8408000000 8b45f4 e9???????? 6802000080 6a00 6800000000 6a00 }
            // n = 7, score = 100
            //   0f8408000000         | je                  0xe
            //   8b45f4               | mov                 eax, dword ptr [ebp - 0xc]
            //   e9????????           |                     
            //   6802000080           | push                0x80000002
            //   6a00                 | push                0
            //   6800000000           | push                0
            //   6a00                 | push                0

        $sequence_2 = { 8b16 6a11 57 6aff 50 8bce ff5268 }
            // n = 7, score = 100
            //   8b16                 | mov                 edx, dword ptr [esi]
            //   6a11                 | push                0x11
            //   57                   | push                edi
            //   6aff                 | push                -1
            //   50                   | push                eax
            //   8bce                 | mov                 ecx, esi
            //   ff5268               | call                dword ptr [edx + 0x68]

        $sequence_3 = { 8bf9 56 ff15???????? 8b476c 83e800 0f8498000000 }
            // n = 6, score = 100
            //   8bf9                 | mov                 edi, ecx
            //   56                   | push                esi
            //   ff15????????         |                     
            //   8b476c               | mov                 eax, dword ptr [edi + 0x6c]
            //   83e800               | sub                 eax, 0
            //   0f8498000000         | je                  0x9e

        $sequence_4 = { e9???????? 8a5101 88542440 8b4c2440 81e1ff000000 668b144d00a55f00 8b4c2414 }
            // n = 7, score = 100
            //   e9????????           |                     
            //   8a5101               | mov                 dl, byte ptr [ecx + 1]
            //   88542440             | mov                 byte ptr [esp + 0x40], dl
            //   8b4c2440             | mov                 ecx, dword ptr [esp + 0x40]
            //   81e1ff000000         | and                 ecx, 0xff
            //   668b144d00a55f00     | mov                 dx, word ptr [ecx*2 + 0x5fa500]
            //   8b4c2414             | mov                 ecx, dword ptr [esp + 0x14]

        $sequence_5 = { 741e 8bce 57 33c0 8d7a08 c1e902 c70201000000 }
            // n = 7, score = 100
            //   741e                 | je                  0x20
            //   8bce                 | mov                 ecx, esi
            //   57                   | push                edi
            //   33c0                 | xor                 eax, eax
            //   8d7a08               | lea                 edi, [edx + 8]
            //   c1e902               | shr                 ecx, 2
            //   c70201000000         | mov                 dword ptr [edx], 1

        $sequence_6 = { 3bc8 0f8f85010000 6a01 6803000000 6a01 6801000000 e8???????? }
            // n = 7, score = 100
            //   3bc8                 | cmp                 ecx, eax
            //   0f8f85010000         | jg                  0x18b
            //   6a01                 | push                1
            //   6803000000           | push                3
            //   6a01                 | push                1
            //   6801000000           | push                1
            //   e8????????           |                     

        $sequence_7 = { 68???????? 56 e8???????? 83c408 8b4e7c 81e1???????? 81f900002000 }
            // n = 7, score = 100
            //   68????????           |                     
            //   56                   | push                esi
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   8b4e7c               | mov                 ecx, dword ptr [esi + 0x7c]
            //   81e1????????         |                     
            //   81f900002000         | cmp                 ecx, 0x200000

        $sequence_8 = { db45f8 dd5dc4 dd45cc dc65c4 dc1d???????? dfe0 f6c401 }
            // n = 7, score = 100
            //   db45f8               | fild                dword ptr [ebp - 8]
            //   dd5dc4               | fstp                qword ptr [ebp - 0x3c]
            //   dd45cc               | fld                 qword ptr [ebp - 0x34]
            //   dc65c4               | fsub                qword ptr [ebp - 0x3c]
            //   dc1d????????         |                     
            //   dfe0                 | fnstsw              ax
            //   f6c401               | test                ah, 1

        $sequence_9 = { 51 68d8070000 c744241c06000000 c744243800000000 c744243c00000000 c744242002000000 89542424 }
            // n = 7, score = 100
            //   51                   | push                ecx
            //   68d8070000           | push                0x7d8
            //   c744241c06000000     | mov                 dword ptr [esp + 0x1c], 6
            //   c744243800000000     | mov                 dword ptr [esp + 0x38], 0
            //   c744243c00000000     | mov                 dword ptr [esp + 0x3c], 0
            //   c744242002000000     | mov                 dword ptr [esp + 0x20], 2
            //   89542424             | mov                 dword ptr [esp + 0x24], edx

    condition:
        7 of them and filesize < 5177344
}