rule win_bqtlock_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.bqtlock."
        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.bqtlock"
        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 = { 4d85c9 742f 660f1f840000000000 8b4810 85c9 0f84b5000000 488b00 }
            // n = 7, score = 100
            //   4d85c9               | lea                 ecx, [ebx + 0xb0]
            //   742f                 | dec                 esp
            //   660f1f840000000000     | lea    ebx, [ebp - 0x30]
            //   8b4810               | dec                 eax
            //   85c9                 | mov                 dword ptr [ebp - 0x18], eax
            //   0f84b5000000         | inc                 ecx
            //   488b00               | movzx               eax, byte ptr [edi + 2]

        $sequence_1 = { 53 4883ec20 4889cb 488d0dd1cc0000 e8???????? 4889c2 488b03 }
            // n = 7, score = 100
            //   53                   | nop                 word ptr cs:[eax + eax]
            //   4883ec20             | dec                 ecx
            //   4889cb               | arpl                word ptr [esp + ebx*4], ax
            //   488d0dd1cc0000       | dec                 ecx
            //   e8????????           |                     
            //   4889c2               | mov                 ecx, dword ptr [esi + eax*8]
            //   488b03               | dec                 ebp

        $sequence_2 = { 807b7900 747d 80bb9000000000 7443 488b4308 31d2 48394310 }
            // n = 7, score = 100
            //   807b7900             | pop                 esi
            //   747d                 | ret                 
            //   80bb9000000000       | dec                 eax
            //   7443                 | lea                 edx, [0xab447]
            //   488b4308             | dec                 eax
            //   31d2                 | mov                 ecx, esi
            //   48394310             | jne                 0x17c

        $sequence_3 = { 488d8bc8000000 488903 4883c028 48c783a001000000000000 488983c8000000 0f1183b0010000 0f1183c0010000 }
            // n = 7, score = 100
            //   488d8bc8000000       | dec                 ecx
            //   488903               | mov                 eax, edi
            //   4883c028             | dec                 ecx
            //   48c783a001000000000000     | mov    ecx, eax
            //   488983c8000000       | dec                 eax
            //   0f1183b0010000       | test                eax, eax
            //   0f1183c0010000       | je                  0x1a37

        $sequence_4 = { 66480f6ec0 0f114310 660fefc0 0f114320 0f114330 e8???????? 488d05850f0b00 }
            // n = 7, score = 100
            //   66480f6ec0           | mov                 ecx, esi
            //   0f114310             | test                eax, eax
            //   660fefc0             | pop                 ebx
            //   0f114320             | pop                 esi
            //   0f114330             | ret                 
            //   e8????????           |                     
            //   488d05850f0b00       | dec                 eax

        $sequence_5 = { e8???????? 488b8300010000 483dff000000 0f8449020000 488d5001 48899300010000 41b901000000 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   488b8300010000       | lea                 esp, [ebx + 0x10]
            //   483dff000000         | mov                 byte ptr [ebx + 0x10], 0
            //   0f8449020000         | dec                 eax
            //   488d5001             | mov                 eax, dword ptr [esp + 0x58]
            //   48899300010000       | dec                 esp
            //   41b901000000         | mov                 dword ptr [ebx], esp

        $sequence_6 = { 49894500 4d8b3424 e9???????? e8???????? 90 90 90 }
            // n = 7, score = 100
            //   49894500             | lea                 eax, [ebp + 0x23f]
            //   4d8b3424             | dec                 eax
            //   e9????????           |                     
            //   e8????????           |                     
            //   90                   | lea                 ecx, [ebp + 0xa0f]
            //   90                   | dec                 eax
            //   90                   | lea                 edx, [0xfe4a8]

        $sequence_7 = { 90 488d4dd4 488d1501561000 488b4520 4989c8 4889c1 e8???????? }
            // n = 7, score = 100
            //   90                   | mov                 eax, dword ptr [ebx]
            //   488d4dd4             | mov                 eax, dword ptr [eax - 8]
            //   488d1501561000       | test                eax, eax
            //   488b4520             | jle                 0xb87
            //   4989c8               | dec                 esp
            //   4889c1               | mov                 edx, ebp
            //   e8????????           |                     

        $sequence_8 = { 4c8d0478 e8???????? 488b35???????? 488b842498000000 482b06 0f85a2010000 4881c4a8000000 }
            // n = 7, score = 100
            //   4c8d0478             | mov                 ecx, dword ptr [esp + 0x58]
            //   e8????????           |                     
            //   488b35????????       |                     
            //   488b842498000000     | call                dword ptr [eax + 0x40]
            //   482b06               | inc                 esp
            //   0f85a2010000         | mov                 edx, dword ptr [esp + 0x6c]
            //   4881c4a8000000       | inc                 ecx

        $sequence_9 = { 742b 488b3d???????? 488b442458 482b07 0f8586010000 4889f0 4883c460 }
            // n = 7, score = 100
            //   742b                 | dec                 eax
            //   488b3d????????       |                     
            //   488b442458           | mov                 eax, 0xffffffff
            //   482b07               | je                  0xc5
            //   0f8586010000         | dec                 eax
            //   4889f0               | sub                 ebx, 1
            //   4883c460             | inc                 ebp

    condition:
        7 of them and filesize < 4444160
}