rule win_mosaic_regressor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        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 = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        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 = { 6a00 668917 ffd5 6a00 }
            // n = 4, score = 100
            //   6a00                 | push                0
            //   668917               | mov                 word ptr [edi], dx
            //   ffd5                 | call                ebp
            //   6a00                 | push                0

        $sequence_1 = { 741f 6a00 8d45f8 50 8d34fd24aa0010 ff36 e8???????? }
            // n = 7, score = 100
            //   741f                 | je                  0x21
            //   6a00                 | push                0
            //   8d45f8               | lea                 eax, [ebp - 8]
            //   50                   | push                eax
            //   8d34fd24aa0010       | lea                 esi, [edi*8 + 0x1000aa24]
            //   ff36                 | push                dword ptr [esi]
            //   e8????????           |                     

        $sequence_2 = { 8bff 55 8bec 8b4508 ff34c578a10010 ff15???????? 5d }
            // n = 7, score = 100
            //   8bff                 | mov                 edi, edi
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   ff34c578a10010       | push                dword ptr [eax*8 + 0x1000a178]
            //   ff15????????         |                     
            //   5d                   | pop                 ebp

        $sequence_3 = { 897e70 c686c800000043 c6864b01000043 c7466890a30010 6a0d e8???????? 59 }
            // n = 7, score = 100
            //   897e70               | mov                 dword ptr [esi + 0x70], edi
            //   c686c800000043       | mov                 byte ptr [esi + 0xc8], 0x43
            //   c6864b01000043       | mov                 byte ptr [esi + 0x14b], 0x43
            //   c7466890a30010       | mov                 dword ptr [esi + 0x68], 0x1000a390
            //   6a0d                 | push                0xd
            //   e8????????           |                     
            //   59                   | pop                 ecx

        $sequence_4 = { 8b15???????? 89480c 8b0d???????? 895010 894814 }
            // n = 5, score = 100
            //   8b15????????         |                     
            //   89480c               | mov                 dword ptr [eax + 0xc], ecx
            //   8b0d????????         |                     
            //   895010               | mov                 dword ptr [eax + 0x10], edx
            //   894814               | mov                 dword ptr [eax + 0x14], ecx

        $sequence_5 = { 8bec 8b4508 ff34c578a10010 ff15???????? 5d c3 6a0c }
            // n = 7, score = 100
            //   8bec                 | mov                 ebp, esp
            //   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 = { 7d10 8a8c181d010000 8888b8a60010 40 ebe6 ff35???????? ff15???????? }
            // n = 7, score = 100
            //   7d10                 | jge                 0x12
            //   8a8c181d010000       | mov                 cl, byte ptr [eax + ebx + 0x11d]
            //   8888b8a60010         | mov                 byte ptr [eax + 0x1000a6b8], cl
            //   40                   | inc                 eax
            //   ebe6                 | jmp                 0xffffffe8
            //   ff35????????         |                     
            //   ff15????????         |                     

        $sequence_7 = { 8bec 8b4508 33c9 3b04cdb0a80010 7413 41 83f92d }
            // n = 7, score = 100
            //   8bec                 | mov                 ebp, esp
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   33c9                 | xor                 ecx, ecx
            //   3b04cdb0a80010       | cmp                 eax, dword ptr [ecx*8 + 0x1000a8b0]
            //   7413                 | je                  0x15
            //   41                   | inc                 ecx
            //   83f92d               | cmp                 ecx, 0x2d

        $sequence_8 = { 8d8c246c010000 51 6a00 ffd5 8d842464010000 48 8d4900 }
            // n = 7, score = 100
            //   8d8c246c010000       | lea                 ecx, [esp + 0x16c]
            //   51                   | push                ecx
            //   6a00                 | push                0
            //   ffd5                 | call                ebp
            //   8d842464010000       | lea                 eax, [esp + 0x164]
            //   48                   | dec                 eax
            //   8d4900               | lea                 ecx, [ecx]

        $sequence_9 = { c1e902 f3a5 8bc8 83e103 f3a4 8dbc246c020000 4f }
            // n = 7, score = 100
            //   c1e902               | shr                 ecx, 2
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   8bc8                 | mov                 ecx, eax
            //   83e103               | and                 ecx, 3
            //   f3a4                 | rep movsb           byte ptr es:[edi], byte ptr [esi]
            //   8dbc246c020000       | lea                 edi, [esp + 0x26c]
            //   4f                   | dec                 edi

    condition:
        7 of them and filesize < 113664
}