rule win_blackbyte_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.blackbyte."
        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.blackbyte"
        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 = { 3bc2 72f4 b8ffffffff 4883c420 }
            // n = 4, score = 200
            //   3bc2                 | sub                 esp, 0x38
            //   72f4                 | dec                 eax
            //   b8ffffffff           | mov                 dword ptr [esp + 0x30], ebp
            //   4883c420             | dec                 eax

        $sequence_1 = { 3bc1 7573 488d4c2448 664585c0 740b }
            // n = 5, score = 200
            //   3bc1                 | dec                 ecx
            //   7573                 | lea                 edi, [edx + ecx]
            //   488d4c2448           | jne                 0xc
            //   664585c0             | dec                 ecx
            //   740b                 | mov                 dword ptr [edx + ecx], eax

        $sequence_2 = { 3bc7 7ce0 eb03 488bda }
            // n = 4, score = 200
            //   3bc7                 | mov                 eax, ebx
            //   7ce0                 | dec                 eax
            //   eb03                 | mov                 eax, esi
            //   488bda               | dec                 eax

        $sequence_3 = { 493b6610 767b 4883ec38 48896c2430 488d6c2430 4889442440 49c7c500000000 }
            // n = 7, score = 200
            //   493b6610             | mov                 ebx, edx
            //   767b                 | dec                 eax
            //   4883ec38             | mov                 edi, ecx
            //   48896c2430           | dec                 ecx
            //   488d6c2430           | cmp                 esp, dword ptr [esi + 0x10]
            //   4889442440           | jbe                 0xef
            //   49c7c500000000       | dec                 eax

        $sequence_4 = { 4981f8c2000000 7554 4c8d4004 4c39c1 733a }
            // n = 5, score = 200
            //   4981f8c2000000       | dec                 esp
            //   7554                 | mov                 dword ptr [esp + 0x70], ecx
            //   4c8d4004             | dec                 eax
            //   4c39c1               | mov                 dword ptr [esp + 0x48], esi
            //   733a                 | dec                 ecx

        $sequence_5 = { 3bc8 7708 41034908 3bc1 }
            // n = 4, score = 200
            //   3bc8                 | jb                  0xfffffff8
            //   7708                 | mov                 eax, 0xffffffff
            //   41034908             | dec                 eax
            //   3bc1                 | add                 esp, 0x20

        $sequence_6 = { 493b6610 0f86e5000000 4883ec58 48896c2450 488d6c2450 e8???????? }
            // n = 6, score = 200
            //   493b6610             | cmp                 eax, 0x12d
            //   0f86e5000000         | jne                 0x4e
            //   4883ec58             | dec                 esp
            //   48896c2450           | lea                 eax, [eax + 1]
            //   488d6c2450           | dec                 esp
            //   e8????????           |                     

        $sequence_7 = { 4989c1 4989c8 488b842480000000 488b8c2488000000 4c894c2470 }
            // n = 5, score = 200
            //   4989c1               | dec                 ecx
            //   4989c8               | mov                 ecx, eax
            //   488b842480000000     | dec                 ecx
            //   488b8c2488000000     | mov                 eax, ecx
            //   4c894c2470           | dec                 eax

        $sequence_8 = { 498d3c11 833d????????00 750b 49890411 }
            // n = 4, score = 200
            //   498d3c11             | jne                 0x4e
            //   833d????????00       |                     
            //   750b                 | dec                 esp
            //   49890411             | lea                 eax, [eax + 1]

        $sequence_9 = { 3bc2 7f2f 4c63d8 85c0 }
            // n = 4, score = 200
            //   3bc2                 | lea                 ebp, [esp + 0x30]
            //   7f2f                 | dec                 eax
            //   4c63d8               | mov                 dword ptr [esp + 0x40], eax
            //   85c0                 | dec                 ecx

        $sequence_10 = { 3bc1 7f4d 33c9 4c63c8 }
            // n = 4, score = 200
            //   3bc1                 | dec                 ecx
            //   7f4d                 | mov                 dword ptr [ecx + edx + 0x10], ecx
            //   33c9                 | dec                 ecx
            //   4c63c8               | lea                 edi, [ecx + edx]

        $sequence_11 = { 3bc7 7f38 33d2 4c63c8 }
            // n = 4, score = 200
            //   3bc7                 | dec                 eax
            //   7f38                 | lea                 ecx, [esp + 0x48]
            //   33d2                 | inc                 bp
            //   4c63c8               | test                eax, eax

        $sequence_12 = { 4981f82d010000 7545 4c8d4001 4c39c1 }
            // n = 4, score = 200
            //   4981f82d010000       | mov                 ecx, eax
            //   7545                 | dec                 ecx
            //   4c8d4001             | mov                 eax, ecx
            //   4c39c1               | dec                 eax

        $sequence_13 = { 498d3c0a 833d????????00 7506 4989040a eb05 e8???????? 488b8424d0000000 }
            // n = 7, score = 200
            //   498d3c0a             | dec                 esp
            //   833d????????00       |                     
            //   7506                 | cmp                 ecx, eax
            //   4989040a             | jae                 0x37
            //   eb05                 | dec                 ecx
            //   e8????????           |                     
            //   488b8424d0000000     | cmp                 eax, 0x12d

        $sequence_14 = { 3bc8 757b 498bc8 6685d2 }
            // n = 4, score = 200
            //   3bc8                 | jg                  0x51
            //   757b                 | xor                 ecx, ecx
            //   498bc8               | dec                 esp
            //   6685d2               | arpl                ax, cx

        $sequence_15 = { 4989c1 4989d8 e9???????? 4889f0 }
            // n = 4, score = 200
            //   4989c1               | sub                 esp, 0x58
            //   4989d8               | dec                 eax
            //   e9????????           |                     
            //   4889f0               | mov                 dword ptr [esp + 0x50], ebp

    condition:
        7 of them and filesize < 9435136
}