rule win_heyoka_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.heyoka."
        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.heyoka"
        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 = { 8b45fc 0302 8945fc 8b4dfc c60100 8b55fc 83c201 }
            // n = 7, score = 100
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   0302                 | add                 eax, dword ptr [edx]
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]
            //   c60100               | mov                 byte ptr [ecx], 0
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]
            //   83c201               | add                 edx, 1

        $sequence_1 = { e8???????? 83c404 89857cd7feff 8b857cd7feff 89858cd7feff 8b8d90d7feff 83c141 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   89857cd7feff         | mov                 dword ptr [ebp - 0x12884], eax
            //   8b857cd7feff         | mov                 eax, dword ptr [ebp - 0x12884]
            //   89858cd7feff         | mov                 dword ptr [ebp - 0x12874], eax
            //   8b8d90d7feff         | mov                 ecx, dword ptr [ebp - 0x12870]
            //   83c141               | add                 ecx, 0x41

        $sequence_2 = { 668b55f4 52 ff15???????? 8b4d0c 8b11 66894202 817df400040000 }
            // n = 7, score = 100
            //   668b55f4             | mov                 dx, word ptr [ebp - 0xc]
            //   52                   | push                edx
            //   ff15????????         |                     
            //   8b4d0c               | mov                 ecx, dword ptr [ebp + 0xc]
            //   8b11                 | mov                 edx, dword ptr [ecx]
            //   66894202             | mov                 word ptr [edx + 2], ax
            //   817df400040000       | cmp                 dword ptr [ebp - 0xc], 0x400

        $sequence_3 = { 894df4 8b55e0 8b8248280100 83c001 8b4de0 898148280100 }
            // n = 6, score = 100
            //   894df4               | mov                 dword ptr [ebp - 0xc], ecx
            //   8b55e0               | mov                 edx, dword ptr [ebp - 0x20]
            //   8b8248280100         | mov                 eax, dword ptr [edx + 0x12848]
            //   83c001               | add                 eax, 1
            //   8b4de0               | mov                 ecx, dword ptr [ebp - 0x20]
            //   898148280100         | mov                 dword ptr [ecx + 0x12848], eax

        $sequence_4 = { 8a02 8801 8b4dfc 894df8 eb07 c745f800000000 8be5 }
            // n = 7, score = 100
            //   8a02                 | mov                 al, byte ptr [edx]
            //   8801                 | mov                 byte ptr [ecx], al
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]
            //   894df8               | mov                 dword ptr [ebp - 8], ecx
            //   eb07                 | jmp                 9
            //   c745f800000000       | mov                 dword ptr [ebp - 8], 0
            //   8be5                 | mov                 esp, ebp

        $sequence_5 = { 0f85ed030000 c785f4fbffff00000000 837d2000 0f849f010000 c685fcfbffff05 }
            // n = 5, score = 100
            //   0f85ed030000         | jne                 0x3f3
            //   c785f4fbffff00000000     | mov    dword ptr [ebp - 0x40c], 0
            //   837d2000             | cmp                 dword ptr [ebp + 0x20], 0
            //   0f849f010000         | je                  0x1a5
            //   c685fcfbffff05       | mov                 byte ptr [ebp - 0x404], 5

        $sequence_6 = { 68???????? e8???????? 83c404 83c8ff e9???????? 8b550c 8b4210 }
            // n = 7, score = 100
            //   68????????           |                     
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   83c8ff               | or                  eax, 0xffffffff
            //   e9????????           |                     
            //   8b550c               | mov                 edx, dword ptr [ebp + 0xc]
            //   8b4210               | mov                 eax, dword ptr [edx + 0x10]

        $sequence_7 = { 8b420c 8138ff000000 7331 8b8de4faffff 51 8b55fc 52 }
            // n = 7, score = 100
            //   8b420c               | mov                 eax, dword ptr [edx + 0xc]
            //   8138ff000000         | cmp                 dword ptr [eax], 0xff
            //   7331                 | jae                 0x33
            //   8b8de4faffff         | mov                 ecx, dword ptr [ebp - 0x51c]
            //   51                   | push                ecx
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]
            //   52                   | push                edx

        $sequence_8 = { 6820090000 8b45fc 50 e8???????? 8b4d08 }
            // n = 5, score = 100
            //   6820090000           | push                0x920
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   50                   | push                eax
            //   e8????????           |                     
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]

        $sequence_9 = { 8955f0 eb14 8b8574d7feff 83c001 898574d7feff e9???????? 8d8d80d7feff }
            // n = 7, score = 100
            //   8955f0               | mov                 dword ptr [ebp - 0x10], edx
            //   eb14                 | jmp                 0x16
            //   8b8574d7feff         | mov                 eax, dword ptr [ebp - 0x1288c]
            //   83c001               | add                 eax, 1
            //   898574d7feff         | mov                 dword ptr [ebp - 0x1288c], eax
            //   e9????????           |                     
            //   8d8d80d7feff         | lea                 ecx, [ebp - 0x12880]

    condition:
        7 of them and filesize < 270336
}