rule win_mosaic_regressor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.mosaic_regressor."
        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.mosaic_regressor"
        malpedia_rule_date = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        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 = { 4f 8a4701 47 84c0 75f8 8d84246c020000 66891f }
            // n = 7, score = 100
            //   4f                   | dec                 edi
            //   8a4701               | mov                 al, byte ptr [edi + 1]
            //   47                   | inc                 edi
            //   84c0                 | test                al, al
            //   75f8                 | jne                 0xfffffffa
            //   8d84246c020000       | lea                 eax, [esp + 0x26c]
            //   66891f               | mov                 word ptr [edi], bx

        $sequence_1 = { 33c0 40 5f 5e c3 8324f578a1001000 }
            // n = 6, score = 100
            //   33c0                 | xor                 eax, eax
            //   40                   | inc                 eax
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   c3                   | ret                 
            //   8324f578a1001000     | and                 dword ptr [esi*8 + 0x1000a178], 0

        $sequence_2 = { 8d34fd24aa0010 ff36 e8???????? 59 50 }
            // n = 5, score = 100
            //   8d34fd24aa0010       | lea                 esi, [edi*8 + 0x1000aa24]
            //   ff36                 | push                dword ptr [esi]
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   50                   | push                eax

        $sequence_3 = { 85c0 7524 a1???????? a3???????? a1???????? c705????????f01a0010 8935???????? }
            // n = 7, score = 100
            //   85c0                 | test                eax, eax
            //   7524                 | jne                 0x26
            //   a1????????           |                     
            //   a3????????           |                     
            //   a1????????           |                     
            //   c705????????f01a0010     |     
            //   8935????????         |                     

        $sequence_4 = { 75f9 56 57 8dbc2480080000 2bc1 8bf1 4f }
            // n = 7, score = 100
            //   75f9                 | jne                 0xfffffffb
            //   56                   | push                esi
            //   57                   | push                edi
            //   8dbc2480080000       | lea                 edi, [esp + 0x880]
            //   2bc1                 | sub                 eax, ecx
            //   8bf1                 | mov                 esi, ecx
            //   4f                   | dec                 edi

        $sequence_5 = { 8b4508 ff34c578a10010 ff15???????? 5d c3 6a0c }
            // n = 6, score = 100
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   ff34c578a10010       | push                dword ptr [eax*8 + 0x1000a178]
            //   ff15????????         |                     
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   6a0c                 | push                0xc

        $sequence_6 = { 81c444010000 c3 8b8c2440010000 33cc 33c0 e8???????? }
            // n = 6, score = 100
            //   81c444010000         | add                 esp, 0x144
            //   c3                   | ret                 
            //   8b8c2440010000       | mov                 ecx, dword ptr [esp + 0x140]
            //   33cc                 | xor                 ecx, esp
            //   33c0                 | xor                 eax, eax
            //   e8????????           |                     

        $sequence_7 = { 0010 b857001023 d18a0688078a 46 }
            // n = 4, score = 100
            //   0010                 | add                 byte ptr [eax], dl
            //   b857001023           | mov                 eax, 0x23100057
            //   d18a0688078a         | ror                 dword ptr [edx - 0x75f877fa], 1
            //   46                   | inc                 esi

        $sequence_8 = { 75f8 8d842480070000 66891f 8bc8 8a10 40 84d2 }
            // n = 7, score = 100
            //   75f8                 | jne                 0xfffffffa
            //   8d842480070000       | lea                 eax, [esp + 0x780]
            //   66891f               | mov                 word ptr [edi], bx
            //   8bc8                 | mov                 ecx, eax
            //   8a10                 | mov                 dl, byte ptr [eax]
            //   40                   | inc                 eax
            //   84d2                 | test                dl, dl

        $sequence_9 = { 83c404 83f801 0f850d030000 6a44 }
            // n = 4, score = 100
            //   83c404               | add                 esp, 4
            //   83f801               | cmp                 eax, 1
            //   0f850d030000         | jne                 0x313
            //   6a44                 | push                0x44

    condition:
        7 of them and filesize < 113664
}