rule win_chthonic_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.chthonic."
        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.chthonic"
        malpedia_rule_date = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        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 = { d3ee 83e601 8975fc eb00 85ff 0f84bd000000 4f }
            // n = 7, score = 600
            //   d3ee                 | shr                 esi, cl
            //   83e601               | and                 esi, 1
            //   8975fc               | mov                 dword ptr [ebp - 4], esi
            //   eb00                 | jmp                 2
            //   85ff                 | test                edi, edi
            //   0f84bd000000         | je                  0xc3
            //   4f                   | dec                 edi

        $sequence_1 = { eb00 85f6 74cb 8b75f8 }
            // n = 4, score = 600
            //   eb00                 | jmp                 2
            //   85f6                 | test                esi, esi
            //   74cb                 | je                  0xffffffcd
            //   8b75f8               | mov                 esi, dword ptr [ebp - 8]

        $sequence_2 = { 83c703 013e 8b36 83c410 f60680 }
            // n = 5, score = 600
            //   83c703               | add                 edi, 3
            //   013e                 | add                 dword ptr [esi], edi
            //   8b36                 | mov                 esi, dword ptr [esi]
            //   83c410               | add                 esp, 0x10
            //   f60680               | test                byte ptr [esi], 0x80

        $sequence_3 = { 8845ff 8d84bdfcfbffff 8b10 8911 }
            // n = 4, score = 600
            //   8845ff               | mov                 byte ptr [ebp - 1], al
            //   8d84bdfcfbffff       | lea                 eax, [ebp + edi*4 - 0x404]
            //   8b10                 | mov                 edx, dword ptr [eax]
            //   8911                 | mov                 dword ptr [ecx], edx

        $sequence_4 = { 0301 03f8 81e7ff000080 7908 4f 81cf00ffffff }
            // n = 6, score = 600
            //   0301                 | add                 eax, dword ptr [ecx]
            //   03f8                 | add                 edi, eax
            //   81e7ff000080         | and                 edi, 0x800000ff
            //   7908                 | jns                 0xa
            //   4f                   | dec                 edi
            //   81cf00ffffff         | or                  edi, 0xffffff00

        $sequence_5 = { 83e601 eb00 8b4df8 8d0c4e }
            // n = 4, score = 600
            //   83e601               | and                 esi, 1
            //   eb00                 | jmp                 2
            //   8b4df8               | mov                 ecx, dword ptr [ebp - 8]
            //   8d0c4e               | lea                 ecx, [esi + ecx*2]

        $sequence_6 = { 6a2a 58 ff7508 66894108 b8ecff0000 }
            // n = 5, score = 600
            //   6a2a                 | push                0x2a
            //   58                   | pop                 eax
            //   ff7508               | push                dword ptr [ebp + 8]
            //   66894108             | mov                 word ptr [ecx + 8], ax
            //   b8ecff0000           | mov                 eax, 0xffec

        $sequence_7 = { d3ee 83e601 eb00 85f6 74cb 8b75f8 83fe02 }
            // n = 7, score = 600
            //   d3ee                 | shr                 esi, cl
            //   83e601               | and                 esi, 1
            //   eb00                 | jmp                 2
            //   85f6                 | test                esi, esi
            //   74cb                 | je                  0xffffffcd
            //   8b75f8               | mov                 esi, dword ptr [ebp - 8]
            //   83fe02               | cmp                 esi, 2

        $sequence_8 = { 013e 8b36 83c410 f60680 7408 }
            // n = 5, score = 600
            //   013e                 | add                 dword ptr [esi], edi
            //   8b36                 | mov                 esi, dword ptr [esi]
            //   83c410               | add                 esp, 0x10
            //   f60680               | test                byte ptr [esi], 0x80
            //   7408                 | je                  0xa

        $sequence_9 = { 46 8908 3bf3 7cbc 33db 33f6 33ff }
            // n = 7, score = 600
            //   46                   | inc                 esi
            //   8908                 | mov                 dword ptr [eax], ecx
            //   3bf3                 | cmp                 esi, ebx
            //   7cbc                 | jl                  0xffffffbe
            //   33db                 | xor                 ebx, ebx
            //   33f6                 | xor                 esi, esi
            //   33ff                 | xor                 edi, edi

    condition:
        7 of them and filesize < 425984
}