rule win_downdelph_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.downdelph."
        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.downdelph"
        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 = { b900000000 e8???????? 8d55f4 8b45fc e8???????? 8b45f4 ba???????? }
            // n = 7, score = 100
            //   b900000000           | mov                 ecx, 0
            //   e8????????           |                     
            //   8d55f4               | lea                 edx, [ebp - 0xc]
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   e8????????           |                     
            //   8b45f4               | mov                 eax, dword ptr [ebp - 0xc]
            //   ba????????           |                     

        $sequence_1 = { 8b17 8d0482 50 8d45c8 }
            // n = 4, score = 100
            //   8b17                 | mov                 edx, dword ptr [edi]
            //   8d0482               | lea                 eax, [edx + eax*4]
            //   50                   | push                eax
            //   8d45c8               | lea                 eax, [ebp - 0x38]

        $sequence_2 = { 8b15???????? e8???????? 83c404 8d55ec }
            // n = 4, score = 100
            //   8b15????????         |                     
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8d55ec               | lea                 edx, [ebp - 0x14]

        $sequence_3 = { 03f1 81e6ff000080 7908 4e 81ce00ffffff 46 0fb68c35bcfeffff }
            // n = 7, score = 100
            //   03f1                 | add                 esi, ecx
            //   81e6ff000080         | and                 esi, 0x800000ff
            //   7908                 | jns                 0xa
            //   4e                   | dec                 esi
            //   81ce00ffffff         | or                  esi, 0xffffff00
            //   46                   | inc                 esi
            //   0fb68c35bcfeffff     | movzx               ecx, byte ptr [ebp + esi - 0x144]

        $sequence_4 = { 8d45f8 ba01000000 e8???????? 837df800 0f8576ffffff }
            // n = 5, score = 100
            //   8d45f8               | lea                 eax, [ebp - 8]
            //   ba01000000           | mov                 edx, 1
            //   e8????????           |                     
            //   837df800             | cmp                 dword ptr [ebp - 8], 0
            //   0f8576ffffff         | jne                 0xffffff7c

        $sequence_5 = { b900000000 e8???????? 33c0 5a 59 59 }
            // n = 6, score = 100
            //   b900000000           | mov                 ecx, 0
            //   e8????????           |                     
            //   33c0                 | xor                 eax, eax
            //   5a                   | pop                 edx
            //   59                   | pop                 ecx
            //   59                   | pop                 ecx

        $sequence_6 = { 8b45fc e8???????? 50 8b45f0 }
            // n = 4, score = 100
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   e8????????           |                     
            //   50                   | push                eax
            //   8b45f0               | mov                 eax, dword ptr [ebp - 0x10]

        $sequence_7 = { 29de eb59 fec5 668b1e }
            // n = 4, score = 100
            //   29de                 | sub                 esi, ebx
            //   eb59                 | jmp                 0x5b
            //   fec5                 | inc                 ch
            //   668b1e               | mov                 bx, word ptr [esi]

        $sequence_8 = { 884415e4 43 80fb08 7537 8d45e4 e8???????? }
            // n = 6, score = 100
            //   884415e4             | mov                 byte ptr [ebp + edx - 0x1c], al
            //   43                   | inc                 ebx
            //   80fb08               | cmp                 bl, 8
            //   7537                 | jne                 0x39
            //   8d45e4               | lea                 eax, [ebp - 0x1c]
            //   e8????????           |                     

        $sequence_9 = { e8???????? 85c0 7467 8b45fc 8b34b8 85f6 }
            // n = 6, score = 100
            //   e8????????           |                     
            //   85c0                 | test                eax, eax
            //   7467                 | je                  0x69
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   8b34b8               | mov                 esi, dword ptr [eax + edi*4]
            //   85f6                 | test                esi, esi

    condition:
        7 of them and filesize < 172032
}