rule win_mespinoza_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-03-28"
        version = "1"
        description = "Detects win.mespinoza."
        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.mespinoza"
        malpedia_rule_date = "20230328"
        malpedia_hash = "9d2d75cef573c1c2d861f5197df8f563b05a305d"
        malpedia_version = "20230407"
        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 = { 50 e8???????? 83c404 894574 8bf0 897544 ff730c }
            // n = 7, score = 200
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   894574               | mov                 dword ptr [ebp + 0x74], eax
            //   8bf0                 | mov                 esi, eax
            //   897544               | mov                 dword ptr [ebp + 0x44], esi
            //   ff730c               | push                dword ptr [ebx + 0xc]

        $sequence_1 = { 8bf1 8975f0 8b7d18 8b5d1c 6a00 8975ec e8???????? }
            // n = 7, score = 200
            //   8bf1                 | mov                 esi, ecx
            //   8975f0               | mov                 dword ptr [ebp - 0x10], esi
            //   8b7d18               | mov                 edi, dword ptr [ebp + 0x18]
            //   8b5d1c               | mov                 ebx, dword ptr [ebp + 0x1c]
            //   6a00                 | push                0
            //   8975ec               | mov                 dword ptr [ebp - 0x14], esi
            //   e8????????           |                     

        $sequence_2 = { 50 e8???????? 83c40c 50 6a00 8d4d9c c645fc01 }
            // n = 7, score = 200
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   50                   | push                eax
            //   6a00                 | push                0
            //   8d4d9c               | lea                 ecx, [ebp - 0x64]
            //   c645fc01             | mov                 byte ptr [ebp - 4], 1

        $sequence_3 = { ff75f0 8bcb ff502c 8b4dec 8bc6 2b45e8 }
            // n = 6, score = 200
            //   ff75f0               | push                dword ptr [ebp - 0x10]
            //   8bcb                 | mov                 ecx, ebx
            //   ff502c               | call                dword ptr [eax + 0x2c]
            //   8b4dec               | mov                 ecx, dword ptr [ebp - 0x14]
            //   8bc6                 | mov                 eax, esi
            //   2b45e8               | sub                 eax, dword ptr [ebp - 0x18]

        $sequence_4 = { 314c2418 0fb6c2 c1ea08 8b04c523924700 }
            // n = 4, score = 200
            //   314c2418             | xor                 dword ptr [esp + 0x18], ecx
            //   0fb6c2               | movzx               eax, dl
            //   c1ea08               | shr                 edx, 8
            //   8b04c523924700       | mov                 eax, dword ptr [eax*8 + 0x479223]

        $sequence_5 = { c1f906 6bd030 8b0c8d00b04700 804c112802 }
            // n = 4, score = 200
            //   c1f906               | sar                 ecx, 6
            //   6bd030               | imul                edx, eax, 0x30
            //   8b0c8d00b04700       | mov                 ecx, dword ptr [ecx*4 + 0x47b000]
            //   804c112802           | or                  byte ptr [ecx + edx + 0x28], 2

        $sequence_6 = { 5d ff6010 55 8bec ff7508 ffb1b8000000 e8???????? }
            // n = 7, score = 200
            //   5d                   | pop                 ebp
            //   ff6010               | jmp                 dword ptr [eax + 0x10]
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   ff7508               | push                dword ptr [ebp + 8]
            //   ffb1b8000000         | push                dword ptr [ecx + 0xb8]
            //   e8????????           |                     

        $sequence_7 = { 6a01 e8???????? 56 6a01 8d4dc0 e8???????? 8b4508 }
            // n = 7, score = 200
            //   6a01                 | push                1
            //   e8????????           |                     
            //   56                   | push                esi
            //   6a01                 | push                1
            //   8d4dc0               | lea                 ecx, [ebp - 0x40]
            //   e8????????           |                     
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]

        $sequence_8 = { 75e2 8b5dec 8b75f0 83fe01 0f8679000000 8b4dd8 }
            // n = 6, score = 200
            //   75e2                 | jne                 0xffffffe4
            //   8b5dec               | mov                 ebx, dword ptr [ebp - 0x14]
            //   8b75f0               | mov                 esi, dword ptr [ebp - 0x10]
            //   83fe01               | cmp                 esi, 1
            //   0f8679000000         | jbe                 0x7f
            //   8b4dd8               | mov                 ecx, dword ptr [ebp - 0x28]

        $sequence_9 = { 85d2 7407 e8???????? eb05 e8???????? 83c640 c745fcffffffff }
            // n = 7, score = 200
            //   85d2                 | test                edx, edx
            //   7407                 | je                  9
            //   e8????????           |                     
            //   eb05                 | jmp                 7
            //   e8????????           |                     
            //   83c640               | add                 esi, 0x40
            //   c745fcffffffff       | mov                 dword ptr [ebp - 4], 0xffffffff

    condition:
        7 of them and filesize < 1091584
}