rule win_mbrlock_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.mbrlock."
        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.mbrlock"
        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 = { 68205c0110 6a01 6839060000 68d4580110 e8???????? 83c410 8bb654020000 }
            // n = 7, score = 100
            //   68205c0110           | push                0x10015c20
            //   6a01                 | push                1
            //   6839060000           | push                0x639
            //   68d4580110           | push                0x100158d4
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10
            //   8bb654020000         | mov                 esi, dword ptr [esi + 0x254]

        $sequence_1 = { 7518 687c510110 50 68fb030000 68804d0110 e8???????? 83c410 }
            // n = 7, score = 100
            //   7518                 | jne                 0x1a
            //   687c510110           | push                0x1001517c
            //   50                   | push                eax
            //   68fb030000           | push                0x3fb
            //   68804d0110           | push                0x10014d80
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10

        $sequence_2 = { 84c3 7521 8ad0 b980850110 0ad3 8815???????? }
            // n = 6, score = 100
            //   84c3                 | test                bl, al
            //   7521                 | jne                 0x23
            //   8ad0                 | mov                 dl, al
            //   b980850110           | mov                 ecx, 0x10018580
            //   0ad3                 | or                  dl, bl
            //   8815????????         |                     

        $sequence_3 = { 2bc1 33c9 8bf0 25ff7f0000 c1ee0f 8a8e908a4a00 0fafc8 }
            // n = 7, score = 100
            //   2bc1                 | sub                 eax, ecx
            //   33c9                 | xor                 ecx, ecx
            //   8bf0                 | mov                 esi, eax
            //   25ff7f0000           | and                 eax, 0x7fff
            //   c1ee0f               | shr                 esi, 0xf
            //   8a8e908a4a00         | mov                 cl, byte ptr [esi + 0x4a8a90]
            //   0fafc8               | imul                ecx, eax

        $sequence_4 = { 6853030000 68804d0110 e8???????? 83c410 8b4e30 68944f0110 51 }
            // n = 7, score = 100
            //   6853030000           | push                0x353
            //   68804d0110           | push                0x10014d80
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10
            //   8b4e30               | mov                 ecx, dword ptr [esi + 0x30]
            //   68944f0110           | push                0x10014f94
            //   51                   | push                ecx

        $sequence_5 = { e8???????? 83c410 85c0 7d46 ba404e0110 bf20000000 8bc6 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10
            //   85c0                 | test                eax, eax
            //   7d46                 | jge                 0x48
            //   ba404e0110           | mov                 edx, 0x10014e40
            //   bf20000000           | mov                 edi, 0x20
            //   8bc6                 | mov                 eax, esi

        $sequence_6 = { 8bf1 33db 8b4608 895e0c 83f8ff 740e 50 }
            // n = 7, score = 100
            //   8bf1                 | mov                 esi, ecx
            //   33db                 | xor                 ebx, ebx
            //   8b4608               | mov                 eax, dword ptr [esi + 8]
            //   895e0c               | mov                 dword ptr [esi + 0xc], ebx
            //   83f8ff               | cmp                 eax, -1
            //   740e                 | je                  0x10
            //   50                   | push                eax

        $sequence_7 = { 3bfb 897de4 7505 e8???????? 689c4e0110 68984e0110 68944e0110 }
            // n = 7, score = 100
            //   3bfb                 | cmp                 edi, ebx
            //   897de4               | mov                 dword ptr [ebp - 0x1c], edi
            //   7505                 | jne                 7
            //   e8????????           |                     
            //   689c4e0110           | push                0x10014e9c
            //   68984e0110           | push                0x10014e98
            //   68944e0110           | push                0x10014e94

        $sequence_8 = { 50 8d4601 50 51 8bcf e8???????? }
            // n = 6, score = 100
            //   50                   | push                eax
            //   8d4601               | lea                 eax, [esi + 1]
            //   50                   | push                eax
            //   51                   | push                ecx
            //   8bcf                 | mov                 ecx, edi
            //   e8????????           |                     

        $sequence_9 = { 3bc7 753d 3bdf 742d 53 ff15???????? 8bf0 }
            // n = 7, score = 100
            //   3bc7                 | cmp                 eax, edi
            //   753d                 | jne                 0x3f
            //   3bdf                 | cmp                 ebx, edi
            //   742d                 | je                  0x2f
            //   53                   | push                ebx
            //   ff15????????         |                     
            //   8bf0                 | mov                 esi, eax

    condition:
        7 of them and filesize < 2031616
}