rule win_simda_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.simda."
        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.simda"
        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 = { 40 3b4604 72f1 894e04 }
            // n = 4, score = 700
            //   40                   | inc                 eax
            //   3b4604               | cmp                 eax, dword ptr [esi + 4]
            //   72f1                 | jb                  0xfffffff3
            //   894e04               | mov                 dword ptr [esi + 4], ecx

        $sequence_1 = { c1e310 03d3 c1e110 0b4df8 83cbff }
            // n = 5, score = 700
            //   c1e310               | shl                 ebx, 0x10
            //   03d3                 | add                 edx, ebx
            //   c1e110               | shl                 ecx, 0x10
            //   0b4df8               | or                  ecx, dword ptr [ebp - 8]
            //   83cbff               | or                  ebx, 0xffffffff

        $sequence_2 = { 51 c685f8feffff00 e8???????? 8b35???????? }
            // n = 4, score = 700
            //   51                   | push                ecx
            //   c685f8feffff00       | mov                 byte ptr [ebp - 0x108], 0
            //   e8????????           |                     
            //   8b35????????         |                     

        $sequence_3 = { 2bd7 f7c20000ffff 7404 48 034d10 8b5508 }
            // n = 6, score = 700
            //   2bd7                 | sub                 edx, edi
            //   f7c20000ffff         | test                edx, 0xffff0000
            //   7404                 | je                  6
            //   48                   | dec                 eax
            //   034d10               | add                 ecx, dword ptr [ebp + 0x10]
            //   8b5508               | mov                 edx, dword ptr [ebp + 8]

        $sequence_4 = { 83f906 7519 8b85e8feffff 85c0 7505 8d41ff eb0f }
            // n = 7, score = 700
            //   83f906               | cmp                 ecx, 6
            //   7519                 | jne                 0x1b
            //   8b85e8feffff         | mov                 eax, dword ptr [ebp - 0x118]
            //   85c0                 | test                eax, eax
            //   7505                 | jne                 7
            //   8d41ff               | lea                 eax, [ecx - 1]
            //   eb0f                 | jmp                 0x11

        $sequence_5 = { 52 ffd7 85c0 740c 68???????? }
            // n = 5, score = 700
            //   52                   | push                edx
            //   ffd7                 | call                edi
            //   85c0                 | test                eax, eax
            //   740c                 | je                  0xe
            //   68????????           |                     

        $sequence_6 = { 8bf8 0faf7dfc c1e210 0b55f8 3bfa }
            // n = 5, score = 700
            //   8bf8                 | mov                 edi, eax
            //   0faf7dfc             | imul                edi, dword ptr [ebp - 4]
            //   c1e210               | shl                 edx, 0x10
            //   0b55f8               | or                  edx, dword ptr [ebp - 8]
            //   3bfa                 | cmp                 edi, edx

        $sequence_7 = { ffd7 83c408 85c0 74e4 6a0a 6a00 }
            // n = 6, score = 700
            //   ffd7                 | call                edi
            //   83c408               | add                 esp, 8
            //   85c0                 | test                eax, eax
            //   74e4                 | je                  0xffffffe6
            //   6a0a                 | push                0xa
            //   6a00                 | push                0

        $sequence_8 = { 8bd1 c1ea10 8955ec 8bf8 }
            // n = 4, score = 700
            //   8bd1                 | mov                 edx, ecx
            //   c1ea10               | shr                 edx, 0x10
            //   8955ec               | mov                 dword ptr [ebp - 0x14], edx
            //   8bf8                 | mov                 edi, eax

        $sequence_9 = { 85c0 75dd 8b4d0c 8bc3 2bc2 }
            // n = 5, score = 700
            //   85c0                 | test                eax, eax
            //   75dd                 | jne                 0xffffffdf
            //   8b4d0c               | mov                 ecx, dword ptr [ebp + 0xc]
            //   8bc3                 | mov                 eax, ebx
            //   2bc2                 | sub                 eax, edx

    condition:
        7 of them and filesize < 1581056
}