rule win_chewbacca_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.chewbacca."
        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.chewbacca"
        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 = { e8???????? e8???????? 8b4074 85c0 744f 8b4004 890424 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   e8????????           |                     
            //   8b4074               | mov                 eax, dword ptr [eax + 0x74]
            //   85c0                 | test                eax, eax
            //   744f                 | je                  0x51
            //   8b4004               | mov                 eax, dword ptr [eax + 4]
            //   890424               | mov                 dword ptr [esp], eax

        $sequence_1 = { e8???????? 8d4db0 ba???????? 8b45e8 e8???????? 8b55b0 8d45e8 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   8d4db0               | lea                 ecx, [ebp - 0x50]
            //   ba????????           |                     
            //   8b45e8               | mov                 eax, dword ptr [ebp - 0x18]
            //   e8????????           |                     
            //   8b55b0               | mov                 edx, dword ptr [ebp - 0x50]
            //   8d45e8               | lea                 eax, [ebp - 0x18]

        $sequence_2 = { e8???????? eb26 8b432c 85c0 740f 890424 e8???????? }
            // n = 7, score = 100
            //   e8????????           |                     
            //   eb26                 | jmp                 0x28
            //   8b432c               | mov                 eax, dword ptr [ebx + 0x2c]
            //   85c0                 | test                eax, eax
            //   740f                 | je                  0x11
            //   890424               | mov                 dword ptr [esp], eax
            //   e8????????           |                     

        $sequence_3 = { e8???????? 8d45c0 e8???????? 8d45c4 e8???????? 58 85c0 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   8d45c0               | lea                 eax, [ebp - 0x40]
            //   e8????????           |                     
            //   8d45c4               | lea                 eax, [ebp - 0x3c]
            //   e8????????           |                     
            //   58                   | pop                 eax
            //   85c0                 | test                eax, eax

        $sequence_4 = { e9???????? 8b7830 896c2428 8d3417 83fd04 7334 31c0 }
            // n = 7, score = 100
            //   e9????????           |                     
            //   8b7830               | mov                 edi, dword ptr [eax + 0x30]
            //   896c2428             | mov                 dword ptr [esp + 0x28], ebp
            //   8d3417               | lea                 esi, [edi + edx]
            //   83fd04               | cmp                 ebp, 4
            //   7334                 | jae                 0x36
            //   31c0                 | xor                 eax, eax

        $sequence_5 = { e8???????? e8???????? 8b5304 39d6 0f8e91000000 c70424???????? e8???????? }
            // n = 7, score = 100
            //   e8????????           |                     
            //   e8????????           |                     
            //   8b5304               | mov                 edx, dword ptr [ebx + 4]
            //   39d6                 | cmp                 esi, edx
            //   0f8e91000000         | jle                 0x97
            //   c70424????????       |                     
            //   e8????????           |                     

        $sequence_6 = { e8???????? 83f87a 0f857c000000 8b55e4 81fa00020000 7771 42 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   83f87a               | cmp                 eax, 0x7a
            //   0f857c000000         | jne                 0x82
            //   8b55e4               | mov                 edx, dword ptr [ebp - 0x1c]
            //   81fa00020000         | cmp                 edx, 0x200
            //   7771                 | ja                  0x73
            //   42                   | inc                 edx

        $sequence_7 = { e8???????? eb0d ba???????? 8d45ec e8???????? e8???????? 6a65 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   eb0d                 | jmp                 0xf
            //   ba????????           |                     
            //   8d45ec               | lea                 eax, [ebp - 0x14]
            //   e8????????           |                     
            //   e8????????           |                     
            //   6a65                 | push                0x65

        $sequence_8 = { e8???????? e8???????? 8a4305 83e00f 3c05 0f8491000000 c70424???????? }
            // n = 7, score = 100
            //   e8????????           |                     
            //   e8????????           |                     
            //   8a4305               | mov                 al, byte ptr [ebx + 5]
            //   83e00f               | and                 eax, 0xf
            //   3c05                 | cmp                 al, 5
            //   0f8491000000         | je                  0x97
            //   c70424????????       |                     

        $sequence_9 = { 8a4702 c1e010 09c6 09ce 31c0 8a4703 c1e018 }
            // n = 7, score = 100
            //   8a4702               | mov                 al, byte ptr [edi + 2]
            //   c1e010               | shl                 eax, 0x10
            //   09c6                 | or                  esi, eax
            //   09ce                 | or                  esi, ecx
            //   31c0                 | xor                 eax, eax
            //   8a4703               | mov                 al, byte ptr [edi + 3]
            //   c1e018               | shl                 eax, 0x18

    condition:
        7 of them and filesize < 9764864
}