rule win_unidentified_013_korean_malware_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.unidentified_013_korean_malware."
        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.unidentified_013_korean_malware"
        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 = { 83c404 85c0 750e 80fb28 }
            // n = 4, score = 200
            //   83c404               | add                 esp, 4
            //   85c0                 | test                eax, eax
            //   750e                 | jne                 0x10
            //   80fb28               | cmp                 bl, 0x28

        $sequence_1 = { 84c9 75f9 2bc2 8d6801 8d4501 3944241c 761a }
            // n = 7, score = 200
            //   84c9                 | test                cl, cl
            //   75f9                 | jne                 0xfffffffb
            //   2bc2                 | sub                 eax, edx
            //   8d6801               | lea                 ebp, [eax + 1]
            //   8d4501               | lea                 eax, [ebp + 1]
            //   3944241c             | cmp                 dword ptr [esp + 0x1c], eax
            //   761a                 | jbe                 0x1c

        $sequence_2 = { 6a00 ff15???????? 837c243410 720d 8b542420 52 }
            // n = 6, score = 200
            //   6a00                 | push                0
            //   ff15????????         |                     
            //   837c243410           | cmp                 dword ptr [esp + 0x34], 0x10
            //   720d                 | jb                  0xf
            //   8b542420             | mov                 edx, dword ptr [esp + 0x20]
            //   52                   | push                edx

        $sequence_3 = { 8d9c2454010000 8d8c2454050000 897c2414 897c2418 }
            // n = 4, score = 200
            //   8d9c2454010000       | lea                 ebx, [esp + 0x154]
            //   8d8c2454050000       | lea                 ecx, [esp + 0x554]
            //   897c2414             | mov                 dword ptr [esp + 0x14], edi
            //   897c2418             | mov                 dword ptr [esp + 0x18], edi

        $sequence_4 = { 8944240c eb08 c744240cf2030000 8b4c241c 51 ff15???????? 397c240c }
            // n = 7, score = 200
            //   8944240c             | mov                 dword ptr [esp + 0xc], eax
            //   eb08                 | jmp                 0xa
            //   c744240cf2030000     | mov                 dword ptr [esp + 0xc], 0x3f2
            //   8b4c241c             | mov                 ecx, dword ptr [esp + 0x1c]
            //   51                   | push                ecx
            //   ff15????????         |                     
            //   397c240c             | cmp                 dword ptr [esp + 0xc], edi

        $sequence_5 = { 8b7c2418 8b6c2414 8908 8b0d???????? 895004 8b15???????? }
            // n = 6, score = 200
            //   8b7c2418             | mov                 edi, dword ptr [esp + 0x18]
            //   8b6c2414             | mov                 ebp, dword ptr [esp + 0x14]
            //   8908                 | mov                 dword ptr [eax], ecx
            //   8b0d????????         |                     
            //   895004               | mov                 dword ptr [eax + 4], edx
            //   8b15????????         |                     

        $sequence_6 = { 0fb6442e04 3bc1 7412 0fb6542e05 3bd1 7409 0fb6442e06 }
            // n = 7, score = 200
            //   0fb6442e04           | movzx               eax, byte ptr [esi + ebp + 4]
            //   3bc1                 | cmp                 eax, ecx
            //   7412                 | je                  0x14
            //   0fb6542e05           | movzx               edx, byte ptr [esi + ebp + 5]
            //   3bd1                 | cmp                 edx, ecx
            //   7409                 | je                  0xb
            //   0fb6442e06           | movzx               eax, byte ptr [esi + ebp + 6]

        $sequence_7 = { 68e8030000 ffd6 83ef01 75f4 e8???????? }
            // n = 5, score = 200
            //   68e8030000           | push                0x3e8
            //   ffd6                 | call                esi
            //   83ef01               | sub                 edi, 1
            //   75f4                 | jne                 0xfffffff6
            //   e8????????           |                     

        $sequence_8 = { 8d542414 8bde 8d8c2454040000 e8???????? 85c0 0f84fd000000 }
            // n = 6, score = 200
            //   8d542414             | lea                 edx, [esp + 0x14]
            //   8bde                 | mov                 ebx, esi
            //   8d8c2454040000       | lea                 ecx, [esp + 0x454]
            //   e8????????           |                     
            //   85c0                 | test                eax, eax
            //   0f84fd000000         | je                  0x103

        $sequence_9 = { 3bd8 0f8307010000 0fb6543301 8beb b901000000 896c2430 03da }
            // n = 7, score = 200
            //   3bd8                 | cmp                 ebx, eax
            //   0f8307010000         | jae                 0x10d
            //   0fb6543301           | movzx               edx, byte ptr [ebx + esi + 1]
            //   8beb                 | mov                 ebp, ebx
            //   b901000000           | mov                 ecx, 1
            //   896c2430             | mov                 dword ptr [esp + 0x30], ebp
            //   03da                 | add                 ebx, edx

    condition:
        7 of them and filesize < 204800
}