rule win_grillmark_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.grillmark."
        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.grillmark"
        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 = { ff15???????? 8d8568fcffff 50 6802020000 e8???????? 85c0 7408 }
            // n = 7, score = 300
            //   ff15????????         |                     
            //   8d8568fcffff         | lea                 eax, [ebp - 0x398]
            //   50                   | push                eax
            //   6802020000           | push                0x202
            //   e8????????           |                     
            //   85c0                 | test                eax, eax
            //   7408                 | je                  0xa

        $sequence_1 = { 7413 80f922 7506 8065ff00 }
            // n = 4, score = 300
            //   7413                 | je                  0x15
            //   80f922               | cmp                 cl, 0x22
            //   7506                 | jne                 8
            //   8065ff00             | and                 byte ptr [ebp - 1], 0

        $sequence_2 = { 53 53 57 68???????? ebaa }
            // n = 5, score = 300
            //   53                   | push                ebx
            //   53                   | push                ebx
            //   57                   | push                edi
            //   68????????           |                     
            //   ebaa                 | jmp                 0xffffffac

        $sequence_3 = { 83c004 83c104 8d1406 3b5510 72d6 5e 5d }
            // n = 7, score = 300
            //   83c004               | add                 eax, 4
            //   83c104               | add                 ecx, 4
            //   8d1406               | lea                 edx, [esi + eax]
            //   3b5510               | cmp                 edx, dword ptr [ebp + 0x10]
            //   72d6                 | jb                  0xffffffd8
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp

        $sequence_4 = { 33c0 e9???????? 50 e8???????? 59 8945fc }
            // n = 6, score = 300
            //   33c0                 | xor                 eax, eax
            //   e9????????           |                     
            //   50                   | push                eax
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   8945fc               | mov                 dword ptr [ebp - 4], eax

        $sequence_5 = { 8b35???????? 83c40c 85c0 7410 }
            // n = 4, score = 300
            //   8b35????????         |                     
            //   83c40c               | add                 esp, 0xc
            //   85c0                 | test                eax, eax
            //   7410                 | je                  0x12

        $sequence_6 = { 50 8d85bcf8ffff 50 e8???????? 83c430 }
            // n = 5, score = 300
            //   50                   | push                eax
            //   8d85bcf8ffff         | lea                 eax, [ebp - 0x744]
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c430               | add                 esp, 0x30

        $sequence_7 = { 895df4 f3ab 66ab aa 895df8 c745fc20000000 }
            // n = 6, score = 300
            //   895df4               | mov                 dword ptr [ebp - 0xc], ebx
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax
            //   66ab                 | stosw               word ptr es:[edi], ax
            //   aa                   | stosb               byte ptr es:[edi], al
            //   895df8               | mov                 dword ptr [ebp - 8], ebx
            //   c745fc20000000       | mov                 dword ptr [ebp - 4], 0x20

        $sequence_8 = { 56 8d8590deffff 53 50 }
            // n = 4, score = 300
            //   56                   | push                esi
            //   8d8590deffff         | lea                 eax, [ebp - 0x2170]
            //   53                   | push                ebx
            //   50                   | push                eax

        $sequence_9 = { 55 8bec 51 53 57 33ff 68???????? }
            // n = 7, score = 300
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   51                   | push                ecx
            //   53                   | push                ebx
            //   57                   | push                edi
            //   33ff                 | xor                 edi, edi
            //   68????????           |                     

    condition:
        7 of them and filesize < 212992
}