rule win_quirkyloader_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.quirkyloader."
        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.quirkyloader"
        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 = { eb08 498bd0 e8???????? 488bcb 4c8d1569b60300 41ff12 85c0 }
            // n = 7, score = 100
            //   eb08                 | dec                 eax
            //   498bd0               | mov                 edx, dword ptr [ebp - 0x88]
            //   e8????????           |                     
            //   488bcb               | dec                 eax
            //   4c8d1569b60300       | sub                 edx, dword ptr [ebp - 0x48]
            //   41ff12               | dec                 eax
            //   85c0                 | cmp                 edx, 0x12

        $sequence_1 = { e8???????? 488d0dc59c0e00 488b09 48398d80000000 7405 e8???????? 90 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   488d0dc59c0e00       | dec                 eax
            //   488b09               | lea                 ecx, [0x738ec]
            //   48398d80000000       | dec                 eax
            //   7405                 | mov                 ebx, eax
            //   e8????????           |                     
            //   90                   | mov                 ecx, esi

        $sequence_2 = { c744243041000000 4533c9 4c894c2420 4c8d4c2428 488d542430 4533c0 e8???????? }
            // n = 7, score = 100
            //   c744243041000000     | lea                 edx, [ebp + 0x80]
            //   4533c9               | dec                 ecx
            //   4c894c2420           | mov                 ecx, esp
            //   4c8d4c2428           | inc                 ecx
            //   488d542430           | mov                 eax, 1
            //   4533c0               | mov                 dword ptr [esp + 0x20], 1
            //   e8????????           |                     

        $sequence_3 = { e8???????? 448bc8 897c2420 33d2 89542428 8bd5 4c8bc6 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   448bc8               | and                 edx, eax
            //   897c2420             | shl                 edx, cl
            //   33d2                 | inc                 esp
            //   89542428             | mov                 eax, dword ptr [ecx + eax*4]
            //   8bd5                 | inc                 esp
            //   4c8bc6               | test                edx, eax

        $sequence_4 = { eb1c e8???????? 40383f 488bcf e8???????? 488bc8 488b00 }
            // n = 7, score = 100
            //   eb1c                 | dec                 esp
            //   e8????????           |                     
            //   40383f               | lea                 ebx, [esp + 0x1a0]
            //   488bcf               | dec                 ecx
            //   e8????????           |                     
            //   488bc8               | mov                 ebx, dword ptr [ebx + 0x10]
            //   488b00               | jmp                 0x10a4

        $sequence_5 = { b9e8030000 f390 4883e901 75f8 81c7e8030000 e8???????? 482bc6 }
            // n = 7, score = 100
            //   b9e8030000           | mov                 edx, esi
            //   f390                 | nop                 
            //   4883e901             | dec                 eax
            //   75f8                 | add                 esp, 0x38
            //   81c7e8030000         | pop                 ebx
            //   e8????????           |                     
            //   482bc6               | pop                 ebp

        $sequence_6 = { 741f 488d5607 4883e2f8 488d8dff000000 4803d5 48c1e908 48c1ea08 }
            // n = 7, score = 100
            //   741f                 | pop                 esi
            //   488d5607             | je                  0x513
            //   4883e2f8             | dec                 eax
            //   488d8dff000000       | mov                 ecx, ebx
            //   4803d5               | dec                 eax
            //   48c1e908             | mov                 edx, esi
            //   48c1ea08             | inc                 ecx

        $sequence_7 = { e8???????? ebb5 488d0d53370800 e8???????? 488bd8 e8???????? 488bd0 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   ebb5                 | pop                 ebx
            //   488d0d53370800       | pop                 esi
            //   e8????????           |                     
            //   488bd8               | ret                 
            //   e8????????           |                     
            //   488bd0               | dec                 eax

        $sequence_8 = { eb11 488d4c2428 488d159f8d0200 e8???????? 8b5608 488d4c2428 e8???????? }
            // n = 7, score = 100
            //   eb11                 | cmp                 edi, 1
            //   488d4c2428           | jne                 0xc10
            //   488d159f8d0200       | movzx               ebx, word ptr [esi]
            //   e8????????           |                     
            //   8b5608               | lea                 ecx, [ebx - 1]
            //   488d4c2428           | cmp                 ecx, 0xfe
            //   e8????????           |                     

        $sequence_9 = { e8???????? e8???????? e8???????? 48a5 498d4e10 488bd5 e8???????? }
            // n = 7, score = 100
            //   e8????????           |                     
            //   e8????????           |                     
            //   e8????????           |                     
            //   48a5                 | lea                 eax, [0x8251c]
            //   498d4e10             | dec                 eax
            //   488bd5               | lea                 ecx, [esp + 0x40]
            //   e8????????           |                     

    condition:
        7 of them and filesize < 4722688
}