rule win_mewsei_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.mewsei."
        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.mewsei"
        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 = { 6a00 6a01 6a0e 56 ff15???????? 85c0 7411 }
            // n = 7, score = 400
            //   6a00                 | push                0
            //   6a01                 | push                1
            //   6a0e                 | push                0xe
            //   56                   | push                esi
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7411                 | je                  0x13

        $sequence_1 = { a3???????? a3???????? a1???????? 68???????? 50 c705????????03000000 }
            // n = 6, score = 400
            //   a3????????           |                     
            //   a3????????           |                     
            //   a1????????           |                     
            //   68????????           |                     
            //   50                   | push                eax
            //   c705????????03000000     |     

        $sequence_2 = { 85c0 750c 6a01 e8???????? 83c404 ebe3 }
            // n = 6, score = 400
            //   85c0                 | test                eax, eax
            //   750c                 | jne                 0xe
            //   6a01                 | push                1
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   ebe3                 | jmp                 0xffffffe5

        $sequence_3 = { 5b c3 6a00 6a00 57 ff15???????? }
            // n = 6, score = 400
            //   5b                   | pop                 ebx
            //   c3                   | ret                 
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   57                   | push                edi
            //   ff15????????         |                     

        $sequence_4 = { f7d2 c1c70a 03fb 0bd7 33d3 0355d4 8b5df8 }
            // n = 7, score = 400
            //   f7d2                 | not                 edx
            //   c1c70a               | rol                 edi, 0xa
            //   03fb                 | add                 edi, ebx
            //   0bd7                 | or                  edx, edi
            //   33d3                 | xor                 edx, ebx
            //   0355d4               | add                 edx, dword ptr [ebp - 0x2c]
            //   8b5df8               | mov                 ebx, dword ptr [ebp - 8]

        $sequence_5 = { 6a00 8d5117 8bc7 e8???????? b901000000 6a00 6a00 }
            // n = 7, score = 400
            //   6a00                 | push                0
            //   8d5117               | lea                 edx, [ecx + 0x17]
            //   8bc7                 | mov                 eax, edi
            //   e8????????           |                     
            //   b901000000           | mov                 ecx, 1
            //   6a00                 | push                0
            //   6a00                 | push                0

        $sequence_6 = { 83c418 56 ff15???????? 85c0 7409 56 e8???????? }
            // n = 7, score = 400
            //   83c418               | add                 esp, 0x18
            //   56                   | push                esi
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7409                 | je                  0xb
            //   56                   | push                esi
            //   e8????????           |                     

        $sequence_7 = { 2bf1 8d4900 8a140e 881408 }
            // n = 4, score = 400
            //   2bf1                 | sub                 esi, ecx
            //   8d4900               | lea                 ecx, [ecx]
            //   8a140e               | mov                 dl, byte ptr [esi + ecx]
            //   881408               | mov                 byte ptr [eax + ecx], dl

        $sequence_8 = { 7415 8b04b7 85c0 7409 50 e8???????? }
            // n = 6, score = 400
            //   7415                 | je                  0x17
            //   8b04b7               | mov                 eax, dword ptr [edi + esi*4]
            //   85c0                 | test                eax, eax
            //   7409                 | je                  0xb
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_9 = { ff15???????? 85c0 7404 c645fe01 85ff 7409 57 }
            // n = 7, score = 400
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7404                 | je                  6
            //   c645fe01             | mov                 byte ptr [ebp - 2], 1
            //   85ff                 | test                edi, edi
            //   7409                 | je                  0xb
            //   57                   | push                edi

    condition:
        7 of them and filesize < 504832
}