rule win_alphanc_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.alphanc."
        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.alphanc"
        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 = { e9???????? 8b0d???????? 53 53 6af8 6aff e8???????? }
            // n = 7, score = 100
            //   e9????????           |                     
            //   8b0d????????         |                     
            //   53                   | push                ebx
            //   53                   | push                ebx
            //   6af8                 | push                -8
            //   6aff                 | push                -1
            //   e8????????           |                     

        $sequence_1 = { e8???????? 89442438 8b442414 8bce 8b40f8 89442440 0bf8 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   89442438             | mov                 dword ptr [esp + 0x38], eax
            //   8b442414             | mov                 eax, dword ptr [esp + 0x14]
            //   8bce                 | mov                 ecx, esi
            //   8b40f8               | mov                 eax, dword ptr [eax - 8]
            //   89442440             | mov                 dword ptr [esp + 0x40], eax
            //   0bf8                 | or                  edi, eax

        $sequence_2 = { 8bc7 83e021 3c21 7414 68320d0000 68???????? 68a9000000 }
            // n = 7, score = 100
            //   8bc7                 | mov                 eax, edi
            //   83e021               | and                 eax, 0x21
            //   3c21                 | cmp                 al, 0x21
            //   7414                 | je                  0x16
            //   68320d0000           | push                0xd32
            //   68????????           |                     
            //   68a9000000           | push                0xa9

        $sequence_3 = { 8b4610 50 e8???????? 83c404 83f815 7c05 83f81a }
            // n = 7, score = 100
            //   8b4610               | mov                 eax, dword ptr [esi + 0x10]
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   83f815               | cmp                 eax, 0x15
            //   7c05                 | jl                  7
            //   83f81a               | cmp                 eax, 0x1a

        $sequence_4 = { c744244c3b000000 c744246c08020000 e9???????? 83fb21 7516 8b54245c 8b442444 }
            // n = 7, score = 100
            //   c744244c3b000000     | mov                 dword ptr [esp + 0x4c], 0x3b
            //   c744246c08020000     | mov                 dword ptr [esp + 0x6c], 0x208
            //   e9????????           |                     
            //   83fb21               | cmp                 ebx, 0x21
            //   7516                 | jne                 0x18
            //   8b54245c             | mov                 edx, dword ptr [esp + 0x5c]
            //   8b442444             | mov                 eax, dword ptr [esp + 0x44]

        $sequence_5 = { 8b4c2424 89460c 51 e8???????? 8b542430 894610 52 }
            // n = 7, score = 100
            //   8b4c2424             | mov                 ecx, dword ptr [esp + 0x24]
            //   89460c               | mov                 dword ptr [esi + 0xc], eax
            //   51                   | push                ecx
            //   e8????????           |                     
            //   8b542430             | mov                 edx, dword ptr [esp + 0x30]
            //   894610               | mov                 dword ptr [esi + 0x10], eax
            //   52                   | push                edx

        $sequence_6 = { e8???????? 83c420 83f8ff 752a 8b450c 43 83c614 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   83c420               | add                 esp, 0x20
            //   83f8ff               | cmp                 eax, -1
            //   752a                 | jne                 0x2c
            //   8b450c               | mov                 eax, dword ptr [ebp + 0xc]
            //   43                   | inc                 ebx
            //   83c614               | add                 esi, 0x14

        $sequence_7 = { c3 83c530 6a10 8d8e00010000 55 51 e8???????? }
            // n = 7, score = 100
            //   c3                   | ret                 
            //   83c530               | add                 ebp, 0x30
            //   6a10                 | push                0x10
            //   8d8e00010000         | lea                 ecx, [esi + 0x100]
            //   55                   | push                ebp
            //   51                   | push                ecx
            //   e8????????           |                     

        $sequence_8 = { 8a540c64 88540602 8b442410 40 49 89442410 79ec }
            // n = 7, score = 100
            //   8a540c64             | mov                 dl, byte ptr [esp + ecx + 0x64]
            //   88540602             | mov                 byte ptr [esi + eax + 2], dl
            //   8b442410             | mov                 eax, dword ptr [esp + 0x10]
            //   40                   | inc                 eax
            //   49                   | dec                 ecx
            //   89442410             | mov                 dword ptr [esp + 0x10], eax
            //   79ec                 | jns                 0xffffffee

        $sequence_9 = { f7d6 81e6???????? 83c410 0bf1 eb05 bf01000000 6a08 }
            // n = 7, score = 100
            //   f7d6                 | not                 esi
            //   81e6????????         |                     
            //   83c410               | add                 esp, 0x10
            //   0bf1                 | or                  esi, ecx
            //   eb05                 | jmp                 7
            //   bf01000000           | mov                 edi, 1
            //   6a08                 | push                8

    condition:
        7 of them and filesize < 2015232
}