rule win_tinyfluff_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.tinyfluff."
        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.tinyfluff"
        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 = { c1ff06 6bd838 8b04bd50704100 f644032801 7444 837c0318ff 743d }
            // n = 7, score = 200
            //   c1ff06               | sar                 edi, 6
            //   6bd838               | imul                ebx, eax, 0x38
            //   8b04bd50704100       | mov                 eax, dword ptr [edi*4 + 0x417050]
            //   f644032801           | test                byte ptr [ebx + eax + 0x28], 1
            //   7444                 | je                  0x46
            //   837c0318ff           | cmp                 dword ptr [ebx + eax + 0x18], -1
            //   743d                 | je                  0x3f

        $sequence_1 = { 89861c020000 8b45e0 8d4e0c 6a06 8d9094644100 }
            // n = 5, score = 200
            //   89861c020000         | mov                 dword ptr [esi + 0x21c], eax
            //   8b45e0               | mov                 eax, dword ptr [ebp - 0x20]
            //   8d4e0c               | lea                 ecx, [esi + 0xc]
            //   6a06                 | push                6
            //   8d9094644100         | lea                 edx, [eax + 0x416494]

        $sequence_2 = { c1f906 6bf638 8b0c8d50704100 80643128fd }
            // n = 4, score = 200
            //   c1f906               | sar                 ecx, 6
            //   6bf638               | imul                esi, esi, 0x38
            //   8b0c8d50704100       | mov                 ecx, dword ptr [ecx*4 + 0x417050]
            //   80643128fd           | and                 byte ptr [ecx + esi + 0x28], 0xfd

        $sequence_3 = { 6bf038 03348d50704100 837e18ff 740c 837e18fe 7406 804e2880 }
            // n = 7, score = 200
            //   6bf038               | imul                esi, eax, 0x38
            //   03348d50704100       | add                 esi, dword ptr [ecx*4 + 0x417050]
            //   837e18ff             | cmp                 dword ptr [esi + 0x18], -1
            //   740c                 | je                  0xe
            //   837e18fe             | cmp                 dword ptr [esi + 0x18], -2
            //   7406                 | je                  8
            //   804e2880             | or                  byte ptr [esi + 0x28], 0x80

        $sequence_4 = { e8???????? 8904bd50704100 85c0 7514 6a0c }
            // n = 5, score = 200
            //   e8????????           |                     
            //   8904bd50704100       | mov                 dword ptr [edi*4 + 0x417050], eax
            //   85c0                 | test                eax, eax
            //   7514                 | jne                 0x16
            //   6a0c                 | push                0xc

        $sequence_5 = { 57 8d3c85506d4100 8b07 83ceff }
            // n = 4, score = 200
            //   57                   | push                edi
            //   8d3c85506d4100       | lea                 edi, [eax*4 + 0x416d50]
            //   8b07                 | mov                 eax, dword ptr [edi]
            //   83ceff               | or                  esi, 0xffffffff

        $sequence_6 = { 8b4c2450 8d145502000000 8bc1 81fa00100000 7214 }
            // n = 5, score = 200
            //   8b4c2450             | mov                 ecx, dword ptr [esp + 0x50]
            //   8d145502000000       | lea                 edx, [edx*2 + 2]
            //   8bc1                 | mov                 eax, ecx
            //   81fa00100000         | cmp                 edx, 0x1000
            //   7214                 | jb                  0x16

        $sequence_7 = { 83f801 0f82f0010000 83bdbcfbffff08 8d85a8fbffff }
            // n = 4, score = 200
            //   83f801               | cmp                 eax, 1
            //   0f82f0010000         | jb                  0x1f6
            //   83bdbcfbffff08       | cmp                 dword ptr [ebp - 0x444], 8
            //   8d85a8fbffff         | lea                 eax, [ebp - 0x458]

        $sequence_8 = { e8???????? 83c408 8b94240c010000 83fa08 7236 8b8c24f8000000 }
            // n = 6, score = 200
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   8b94240c010000       | mov                 edx, dword ptr [esp + 0x10c]
            //   83fa08               | cmp                 edx, 8
            //   7236                 | jb                  0x38
            //   8b8c24f8000000       | mov                 ecx, dword ptr [esp + 0xf8]

        $sequence_9 = { 750e 8b04bd50704100 807c302900 741d 8d45fc 50 }
            // n = 6, score = 200
            //   750e                 | jne                 0x10
            //   8b04bd50704100       | mov                 eax, dword ptr [edi*4 + 0x417050]
            //   807c302900           | cmp                 byte ptr [eax + esi + 0x29], 0
            //   741d                 | je                  0x1f
            //   8d45fc               | lea                 eax, [ebp - 4]
            //   50                   | push                eax

    condition:
        7 of them and filesize < 245760
}