rule win_badaudio_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.badaudio."
        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.badaudio"
        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 = { 51 50 e8???????? 83c40c 31db 85c0 0f94c3 }
            // n = 7, score = 300
            //   51                   | push                ecx
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   31db                 | xor                 ebx, ebx
            //   85c0                 | test                eax, eax
            //   0f94c3               | sete                bl

        $sequence_1 = { 80f136 884c2440 345c 880424 }
            // n = 4, score = 300
            //   80f136               | xor                 cl, 0x36
            //   884c2440             | mov                 byte ptr [esp + 0x40], cl
            //   345c                 | xor                 al, 0x5c
            //   880424               | mov                 byte ptr [esp], al

        $sequence_2 = { e8???????? 8b7d08 c6470c00 807de000 0f8447ffffff 8b45dc }
            // n = 6, score = 300
            //   e8????????           |                     
            //   8b7d08               | mov                 edi, dword ptr [ebp + 8]
            //   c6470c00             | mov                 byte ptr [edi + 0xc], 0
            //   807de000             | cmp                 byte ptr [ebp - 0x20], 0
            //   0f8447ffffff         | je                  0xffffff4d
            //   8b45dc               | mov                 eax, dword ptr [ebp - 0x24]

        $sequence_3 = { 8d7110 83c0f0 8b1a 8b5204 8945cc 8975c8 894db8 }
            // n = 7, score = 300
            //   8d7110               | lea                 esi, [ecx + 0x10]
            //   83c0f0               | add                 eax, -0x10
            //   8b1a                 | mov                 ebx, dword ptr [edx]
            //   8b5204               | mov                 edx, dword ptr [edx + 4]
            //   8945cc               | mov                 dword ptr [ebp - 0x34], eax
            //   8975c8               | mov                 dword ptr [ebp - 0x38], esi
            //   894db8               | mov                 dword ptr [ebp - 0x48], ecx

        $sequence_4 = { 89c1 c1c11e 89c6 c1c613 31ce c1c00a 31f0 }
            // n = 7, score = 300
            //   89c1                 | mov                 ecx, eax
            //   c1c11e               | rol                 ecx, 0x1e
            //   89c6                 | mov                 esi, eax
            //   c1c613               | rol                 esi, 0x13
            //   31ce                 | xor                 esi, ecx
            //   c1c00a               | rol                 eax, 0xa
            //   31f0                 | xor                 eax, esi

        $sequence_5 = { 7226 83f83f 7714 90 8d4801 894e28 c644062c00 }
            // n = 7, score = 300
            //   7226                 | jb                  0x28
            //   83f83f               | cmp                 eax, 0x3f
            //   7714                 | ja                  0x16
            //   90                   | nop                 
            //   8d4801               | lea                 ecx, [eax + 1]
            //   894e28               | mov                 dword ptr [esi + 0x28], ecx
            //   c644062c00           | mov                 byte ptr [esi + eax + 0x2c], 0

        $sequence_6 = { 51 50 e8???????? 83c40c 8b4614 2b4610 034604 }
            // n = 7, score = 300
            //   51                   | push                ecx
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   8b4614               | mov                 eax, dword ptr [esi + 0x14]
            //   2b4610               | sub                 eax, dword ptr [esi + 0x10]
            //   034604               | add                 eax, dword ptr [esi + 4]

        $sequence_7 = { 3a540803 7540 83c104 83f920 75ce }
            // n = 5, score = 300
            //   3a540803             | cmp                 dl, byte ptr [eax + ecx + 3]
            //   7540                 | jne                 0x42
            //   83c104               | add                 ecx, 4
            //   83f920               | cmp                 ecx, 0x20
            //   75ce                 | jne                 0xffffffd0

        $sequence_8 = { 328fe7000000 884e07 8a442402 3287e8000000 884608 8a442405 3287e9000000 }
            // n = 7, score = 300
            //   328fe7000000         | xor                 cl, byte ptr [edi + 0xe7]
            //   884e07               | mov                 byte ptr [esi + 7], cl
            //   8a442402             | mov                 al, byte ptr [esp + 2]
            //   3287e8000000         | xor                 al, byte ptr [edi + 0xe8]
            //   884608               | mov                 byte ptr [esi + 8], al
            //   8a442405             | mov                 al, byte ptr [esp + 5]
            //   3287e9000000         | xor                 al, byte ptr [edi + 0xe9]

        $sequence_9 = { e8???????? 83c404 50 89e2 8b0e c70600000000 }
            // n = 6, score = 300
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   50                   | push                eax
            //   89e2                 | mov                 edx, esp
            //   8b0e                 | mov                 ecx, dword ptr [esi]
            //   c70600000000         | mov                 dword ptr [esi], 0

    condition:
        7 of them and filesize < 1420288
}