rule win_xiaoba_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        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 = "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 = { bd00ffffff c1e109 c1e008 80e100 03c1 8bc8 b8abaaaa2a }
            // n = 7, score = 100
            //   bd00ffffff           | mov                 ebp, 0xffffff00
            //   c1e109               | shl                 ecx, 9
            //   c1e008               | shl                 eax, 8
            //   80e100               | and                 cl, 0
            //   03c1                 | add                 eax, ecx
            //   8bc8                 | mov                 ecx, eax
            //   b8abaaaa2a           | mov                 eax, 0x2aaaaaab

        $sequence_1 = { 03f7 89542438 33ff eb04 8b742440 85c9 0f8e64010000 }
            // n = 7, score = 100
            //   03f7                 | add                 esi, edi
            //   89542438             | mov                 dword ptr [esp + 0x38], edx
            //   33ff                 | xor                 edi, edi
            //   eb04                 | jmp                 6
            //   8b742440             | mov                 esi, dword ptr [esp + 0x40]
            //   85c9                 | test                ecx, ecx
            //   0f8e64010000         | jle                 0x16a

        $sequence_2 = { 8b39 3937 740b 40 83c104 3bc2 7cf2 }
            // n = 7, score = 100
            //   8b39                 | mov                 edi, dword ptr [ecx]
            //   3937                 | cmp                 dword ptr [edi], esi
            //   740b                 | je                  0xd
            //   40                   | inc                 eax
            //   83c104               | add                 ecx, 4
            //   3bc2                 | cmp                 eax, edx
            //   7cf2                 | jl                  0xfffffff4

        $sequence_3 = { 8b542410 894840 8b4c2414 c7403c01000000 894844 8b4c240c 895048 }
            // n = 7, score = 100
            //   8b542410             | mov                 edx, dword ptr [esp + 0x10]
            //   894840               | mov                 dword ptr [eax + 0x40], ecx
            //   8b4c2414             | mov                 ecx, dword ptr [esp + 0x14]
            //   c7403c01000000       | mov                 dword ptr [eax + 0x3c], 1
            //   894844               | mov                 dword ptr [eax + 0x44], ecx
            //   8b4c240c             | mov                 ecx, dword ptr [esp + 0xc]
            //   895048               | mov                 dword ptr [eax + 0x48], edx

        $sequence_4 = { 8b542424 898150010000 8b442428 899154010000 8b54242c 898158010000 8b442430 }
            // n = 7, score = 100
            //   8b542424             | mov                 edx, dword ptr [esp + 0x24]
            //   898150010000         | mov                 dword ptr [ecx + 0x150], eax
            //   8b442428             | mov                 eax, dword ptr [esp + 0x28]
            //   899154010000         | mov                 dword ptr [ecx + 0x154], edx
            //   8b54242c             | mov                 edx, dword ptr [esp + 0x2c]
            //   898158010000         | mov                 dword ptr [ecx + 0x158], eax
            //   8b442430             | mov                 eax, dword ptr [esp + 0x30]

        $sequence_5 = { 8d542448 51 52 897c2430 895c2434 89742440 ff15???????? }
            // n = 7, score = 100
            //   8d542448             | lea                 edx, [esp + 0x48]
            //   51                   | push                ecx
            //   52                   | push                edx
            //   897c2430             | mov                 dword ptr [esp + 0x30], edi
            //   895c2434             | mov                 dword ptr [esp + 0x34], ebx
            //   89742440             | mov                 dword ptr [esp + 0x40], esi
            //   ff15????????         |                     

        $sequence_6 = { 7470 8b542418 8b442410 8d8c2484000000 51 56 57 }
            // n = 7, score = 100
            //   7470                 | je                  0x72
            //   8b542418             | mov                 edx, dword ptr [esp + 0x18]
            //   8b442410             | mov                 eax, dword ptr [esp + 0x10]
            //   8d8c2484000000       | lea                 ecx, [esp + 0x84]
            //   51                   | push                ecx
            //   56                   | push                esi
            //   57                   | push                edi

        $sequence_7 = { 83f8ff 0f8536ffffff 5f 5e 5d b802000000 5b }
            // n = 7, score = 100
            //   83f8ff               | cmp                 eax, -1
            //   0f8536ffffff         | jne                 0xffffff3c
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp
            //   b802000000           | mov                 eax, 2
            //   5b                   | pop                 ebx

        $sequence_8 = { 8b10 52 e8???????? 83c404 8b4c2474 8901 8d4c2414 }
            // n = 7, score = 100
            //   8b10                 | mov                 edx, dword ptr [eax]
            //   52                   | push                edx
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8b4c2474             | mov                 ecx, dword ptr [esp + 0x74]
            //   8901                 | mov                 dword ptr [ecx], eax
            //   8d4c2414             | lea                 ecx, [esp + 0x14]

        $sequence_9 = { 5f 8bc5 5e 5d 5b 83c45c c20400 }
            // n = 7, score = 100
            //   5f                   | pop                 edi
            //   8bc5                 | mov                 eax, ebp
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp
            //   5b                   | pop                 ebx
            //   83c45c               | add                 esp, 0x5c
            //   c20400               | ret                 4

    condition:
        7 of them and filesize < 5177344
}