rule win_buterat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.buterat."
        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.buterat"
        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 = { ff7608 ff36 e8???????? 8b4514 8b3c85a8c44100 83c40c }
            // n = 6, score = 100
            //   ff7608               | push                dword ptr [esi + 8]
            //   ff36                 | push                dword ptr [esi]
            //   e8????????           |                     
            //   8b4514               | mov                 eax, dword ptr [ebp + 0x14]
            //   8b3c85a8c44100       | mov                 edi, dword ptr [eax*4 + 0x41c4a8]
            //   83c40c               | add                 esp, 0xc

        $sequence_1 = { c3 8bce 69c944010000 8d81a05b4100 8b10 c1e204 }
            // n = 6, score = 100
            //   c3                   | ret                 
            //   8bce                 | mov                 ecx, esi
            //   69c944010000         | imul                ecx, ecx, 0x144
            //   8d81a05b4100         | lea                 eax, [ecx + 0x415ba0]
            //   8b10                 | mov                 edx, dword ptr [eax]
            //   c1e204               | shl                 edx, 4

        $sequence_2 = { 394d18 0f8d4a010000 8b0d???????? 3bcf 750c 66c745d83000 66897dda }
            // n = 7, score = 100
            //   394d18               | cmp                 dword ptr [ebp + 0x18], ecx
            //   0f8d4a010000         | jge                 0x150
            //   8b0d????????         |                     
            //   3bcf                 | cmp                 ecx, edi
            //   750c                 | jne                 0xe
            //   66c745d83000         | mov                 word ptr [ebp - 0x28], 0x30
            //   66897dda             | mov                 word ptr [ebp - 0x26], di

        $sequence_3 = { ff75fc 8d84100cfeffff 8985c0feffff ffd7 56 8d45f8 50 }
            // n = 7, score = 100
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   8d84100cfeffff       | lea                 eax, [eax + edx - 0x1f4]
            //   8985c0feffff         | mov                 dword ptr [ebp - 0x140], eax
            //   ffd7                 | call                edi
            //   56                   | push                esi
            //   8d45f8               | lea                 eax, [ebp - 8]
            //   50                   | push                eax

        $sequence_4 = { 8d45f0 50 668955f8 ffd6 8d45d0 50 8d45e0 }
            // n = 7, score = 100
            //   8d45f0               | lea                 eax, [ebp - 0x10]
            //   50                   | push                eax
            //   668955f8             | mov                 word ptr [ebp - 8], dx
            //   ffd6                 | call                esi
            //   8d45d0               | lea                 eax, [ebp - 0x30]
            //   50                   | push                eax
            //   8d45e0               | lea                 eax, [ebp - 0x20]

        $sequence_5 = { 394518 0f8d73010000 83be8400000001 754b 394d10 7406 837d1005 }
            // n = 7, score = 100
            //   394518               | cmp                 dword ptr [ebp + 0x18], eax
            //   0f8d73010000         | jge                 0x179
            //   83be8400000001       | cmp                 dword ptr [esi + 0x84], 1
            //   754b                 | jne                 0x4d
            //   394d10               | cmp                 dword ptr [ebp + 0x10], ecx
            //   7406                 | je                  8
            //   837d1005             | cmp                 dword ptr [ebp + 0x10], 5

        $sequence_6 = { 8bd8 83fbff 7504 33c0 eb47 57 56 }
            // n = 7, score = 100
            //   8bd8                 | mov                 ebx, eax
            //   83fbff               | cmp                 ebx, -1
            //   7504                 | jne                 6
            //   33c0                 | xor                 eax, eax
            //   eb47                 | jmp                 0x49
            //   57                   | push                edi
            //   56                   | push                esi

        $sequence_7 = { 50 83c60e 56 897df4 c745f801000000 e8???????? }
            // n = 6, score = 100
            //   50                   | push                eax
            //   83c60e               | add                 esi, 0xe
            //   56                   | push                esi
            //   897df4               | mov                 dword ptr [ebp - 0xc], edi
            //   c745f801000000       | mov                 dword ptr [ebp - 8], 1
            //   e8????????           |                     

        $sequence_8 = { 68000000c0 ff750c ffd3 83f8ff }
            // n = 4, score = 100
            //   68000000c0           | push                0xc0000000
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   ffd3                 | call                ebx
            //   83f8ff               | cmp                 eax, -1

        $sequence_9 = { 8975f8 e8???????? 83c414 85c0 7503 }
            // n = 5, score = 100
            //   8975f8               | mov                 dword ptr [ebp - 8], esi
            //   e8????????           |                     
            //   83c414               | add                 esp, 0x14
            //   85c0                 | test                eax, eax
            //   7503                 | jne                 5

    condition:
        7 of them and filesize < 278528
}