rule win_mirrorkey_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.mirrorkey."
        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.mirrorkey"
        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 = { 41 8b7508 03c8 8a1431 }
            // n = 4, score = 100
            //   41                   | inc                 ecx
            //   8b7508               | mov                 esi, dword ptr [ebp + 8]
            //   03c8                 | add                 ecx, eax
            //   8a1431               | mov                 dl, byte ptr [ecx + esi]

        $sequence_1 = { 8945f8 8b441720 03c7 8945fc }
            // n = 4, score = 100
            //   8945f8               | mov                 dword ptr [ebp - 8], eax
            //   8b441720             | mov                 eax, dword ptr [edi + edx + 0x20]
            //   03c7                 | add                 eax, edi
            //   8945fc               | mov                 dword ptr [ebp - 4], eax

        $sequence_2 = { 8a1c19 8d4f01 81e103000080 7905 49 }
            // n = 5, score = 100
            //   8a1c19               | mov                 bl, byte ptr [ecx + ebx]
            //   8d4f01               | lea                 ecx, [edi + 1]
            //   81e103000080         | and                 ecx, 0x80000003
            //   7905                 | jns                 7
            //   49                   | dec                 ecx

        $sequence_3 = { 8a5c1001 84db 7454 8bb5e8feffff }
            // n = 4, score = 100
            //   8a5c1001             | mov                 bl, byte ptr [eax + edx + 1]
            //   84db                 | test                bl, bl
            //   7454                 | je                  0x56
            //   8bb5e8feffff         | mov                 esi, dword ptr [ebp - 0x118]

        $sequence_4 = { 8b7908 8b4d08 8b44171c 8b5c1718 03c7 8945ec }
            // n = 6, score = 100
            //   8b7908               | mov                 edi, dword ptr [ecx + 8]
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   8b44171c             | mov                 eax, dword ptr [edi + edx + 0x1c]
            //   8b5c1718             | mov                 ebx, dword ptr [edi + edx + 0x18]
            //   03c7                 | add                 eax, edi
            //   8945ec               | mov                 dword ptr [ebp - 0x14], eax

        $sequence_5 = { ff15???????? 8b4310 6a00 6a01 56 }
            // n = 5, score = 100
            //   ff15????????         |                     
            //   8b4310               | mov                 eax, dword ptr [ebx + 0x10]
            //   6a00                 | push                0
            //   6a01                 | push                1
            //   56                   | push                esi

        $sequence_6 = { 895dfc 6690 a1???????? be01000000 8b3d???????? a3???????? b8???????? }
            // n = 7, score = 100
            //   895dfc               | mov                 dword ptr [ebp - 4], ebx
            //   6690                 | nop                 
            //   a1????????           |                     
            //   be01000000           | mov                 esi, 1
            //   8b3d????????         |                     
            //   a3????????           |                     
            //   b8????????           |                     

        $sequence_7 = { 8d4901 0fb642ff 3041ff 0fb64203 304103 0fb64207 }
            // n = 6, score = 100
            //   8d4901               | lea                 ecx, [ecx + 1]
            //   0fb642ff             | movzx               eax, byte ptr [edx - 1]
            //   3041ff               | xor                 byte ptr [ecx - 1], al
            //   0fb64203             | movzx               eax, byte ptr [edx + 3]
            //   304103               | xor                 byte ptr [ecx + 3], al
            //   0fb64207             | movzx               eax, byte ptr [edx + 7]

        $sequence_8 = { 50 8d45f8 50 e8???????? 8b4df8 56 8b4914 }
            // n = 7, score = 100
            //   50                   | push                eax
            //   8d45f8               | lea                 eax, [ebp - 8]
            //   50                   | push                eax
            //   e8????????           |                     
            //   8b4df8               | mov                 ecx, dword ptr [ebp - 8]
            //   56                   | push                esi
            //   8b4914               | mov                 ecx, dword ptr [ecx + 0x14]

        $sequence_9 = { 03c7 8945ec 8b441724 03c7 8945f8 }
            // n = 5, score = 100
            //   03c7                 | add                 eax, edi
            //   8945ec               | mov                 dword ptr [ebp - 0x14], eax
            //   8b441724             | mov                 eax, dword ptr [edi + edx + 0x24]
            //   03c7                 | add                 eax, edi
            //   8945f8               | mov                 dword ptr [ebp - 8], eax

    condition:
        7 of them and filesize < 117760
}