rule win_emdivi_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.emdivi."
        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.emdivi"
        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 = { 3bd1 7cf5 6a1e 58 5f c9 c3 }
            // n = 7, score = 300
            //   3bd1                 | cmp                 edx, ecx
            //   7cf5                 | jl                  0xfffffff7
            //   6a1e                 | push                0x1e
            //   58                   | pop                 eax
            //   5f                   | pop                 edi
            //   c9                   | leave               
            //   c3                   | ret                 

        $sequence_1 = { 33d2 f7f7 8bf8 0fb606 c1e802 }
            // n = 5, score = 300
            //   33d2                 | xor                 edx, edx
            //   f7f7                 | div                 edi
            //   8bf8                 | mov                 edi, eax
            //   0fb606               | movzx               eax, byte ptr [esi]
            //   c1e802               | shr                 eax, 2

        $sequence_2 = { ff45fc e8???????? 3945fc 0f8e75ffffff e9???????? 8b45fc }
            // n = 6, score = 300
            //   ff45fc               | inc                 dword ptr [ebp - 4]
            //   e8????????           |                     
            //   3945fc               | cmp                 dword ptr [ebp - 4], eax
            //   0f8e75ffffff         | jle                 0xffffff7b
            //   e9????????           |                     
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]

        $sequence_3 = { 295d08 41 8801 0fb64601 }
            // n = 4, score = 300
            //   295d08               | sub                 dword ptr [ebp + 8], ebx
            //   41                   | inc                 ecx
            //   8801                 | mov                 byte ptr [ecx], al
            //   0fb64601             | movzx               eax, byte ptr [esi + 1]

        $sequence_4 = { 8b4508 ff45f8 85c0 7405 }
            // n = 4, score = 300
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   ff45f8               | inc                 dword ptr [ebp - 8]
            //   85c0                 | test                eax, eax
            //   7405                 | je                  7

        $sequence_5 = { 8955ec 83c006 69c0b979379e 8945fc 8b55f0 c1e802 83e003 }
            // n = 7, score = 300
            //   8955ec               | mov                 dword ptr [ebp - 0x14], edx
            //   83c006               | add                 eax, 6
            //   69c0b979379e         | imul                eax, eax, 0x9e3779b9
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   8b55f0               | mov                 edx, dword ptr [ebp - 0x10]
            //   c1e802               | shr                 eax, 2
            //   83e003               | and                 eax, 3

        $sequence_6 = { 8945f4 8b45e0 83c40c 40 8945f8 8b45dc 8945fc }
            // n = 7, score = 300
            //   8945f4               | mov                 dword ptr [ebp - 0xc], eax
            //   8b45e0               | mov                 eax, dword ptr [ebp - 0x20]
            //   83c40c               | add                 esp, 0xc
            //   40                   | inc                 eax
            //   8945f8               | mov                 dword ptr [ebp - 8], eax
            //   8b45dc               | mov                 eax, dword ptr [ebp - 0x24]
            //   8945fc               | mov                 dword ptr [ebp - 4], eax

        $sequence_7 = { eb04 2bc8 03ca 880c32 42 3bd0 72e5 }
            // n = 7, score = 300
            //   eb04                 | jmp                 6
            //   2bc8                 | sub                 ecx, eax
            //   03ca                 | add                 ecx, edx
            //   880c32               | mov                 byte ptr [edx + esi], cl
            //   42                   | inc                 edx
            //   3bd0                 | cmp                 edx, eax
            //   72e5                 | jb                  0xffffffe7

        $sequence_8 = { c1ef03 33fb 8b5d08 03c7 8bfa 83e703 }
            // n = 6, score = 300
            //   c1ef03               | shr                 edi, 3
            //   33fb                 | xor                 edi, ebx
            //   8b5d08               | mov                 ebx, dword ptr [ebp + 8]
            //   03c7                 | add                 eax, edi
            //   8bfa                 | mov                 edi, edx
            //   83e703               | and                 edi, 3

        $sequence_9 = { 2bca 03c8 eb04 2bc8 03ca }
            // n = 5, score = 300
            //   2bca                 | sub                 ecx, edx
            //   03c8                 | add                 ecx, eax
            //   eb04                 | jmp                 6
            //   2bc8                 | sub                 ecx, eax
            //   03ca                 | add                 ecx, edx

    condition:
        7 of them and filesize < 581632
}