rule win_varenyky_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.varenyky."
        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.varenyky"
        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 = { 59 40 00b859400023 d18a0688078a }
            // n = 4, score = 100
            //   59                   | pop                 ecx
            //   40                   | inc                 eax
            //   00b859400023         | add                 byte ptr [eax + 0x23004059], bh
            //   d18a0688078a         | ror                 dword ptr [edx - 0x75f877fa], 1

        $sequence_1 = { 030cb5401efd00 eb02 8bca f641247f 7591 83f8ff 7419 }
            // n = 7, score = 100
            //   030cb5401efd00       | add                 ecx, dword ptr [esi*4 + 0xfd1e40]
            //   eb02                 | jmp                 4
            //   8bca                 | mov                 ecx, edx
            //   f641247f             | test                byte ptr [ecx + 0x24], 0x7f
            //   7591                 | jne                 0xffffff93
            //   83f8ff               | cmp                 eax, -1
            //   7419                 | je                  0x1b

        $sequence_2 = { 8d8c2454010000 68???????? 51 e8???????? 8d84245c010000 83c40c }
            // n = 6, score = 100
            //   8d8c2454010000       | lea                 ecx, [esp + 0x154]
            //   68????????           |                     
            //   51                   | push                ecx
            //   e8????????           |                     
            //   8d84245c010000       | lea                 eax, [esp + 0x15c]
            //   83c40c               | add                 esp, 0xc

        $sequence_3 = { 50 668954240c ff15???????? 6a10 }
            // n = 4, score = 100
            //   50                   | push                eax
            //   668954240c           | mov                 word ptr [esp + 0xc], dx
            //   ff15????????         |                     
            //   6a10                 | push                0x10

        $sequence_4 = { e8???????? 8bc6 c1f805 8b0485401efd00 83e61f c1e606 59 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   8bc6                 | mov                 eax, esi
            //   c1f805               | sar                 eax, 5
            //   8b0485401efd00       | mov                 eax, dword ptr [eax*4 + 0xfd1e40]
            //   83e61f               | and                 esi, 0x1f
            //   c1e606               | shl                 esi, 6
            //   59                   | pop                 ecx

        $sequence_5 = { 56 e8???????? 59 8945e4 8b7508 c7465c98c84000 33ff }
            // n = 7, score = 100
            //   56                   | push                esi
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   8945e4               | mov                 dword ptr [ebp - 0x1c], eax
            //   8b7508               | mov                 esi, dword ptr [ebp + 8]
            //   c7465c98c84000       | mov                 dword ptr [esi + 0x5c], 0x40c898
            //   33ff                 | xor                 edi, edi

        $sequence_6 = { 6803010000 8d84249d010000 6a00 50 e8???????? }
            // n = 5, score = 100
            //   6803010000           | push                0x103
            //   8d84249d010000       | lea                 eax, [esp + 0x19d]
            //   6a00                 | push                0
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_7 = { 85c0 0f8e13010000 6887130000 8d542435 6a00 52 c644243c00 }
            // n = 7, score = 100
            //   85c0                 | test                eax, eax
            //   0f8e13010000         | jle                 0x119
            //   6887130000           | push                0x1387
            //   8d542435             | lea                 edx, [esp + 0x35]
            //   6a00                 | push                0
            //   52                   | push                edx
            //   c644243c00           | mov                 byte ptr [esp + 0x3c], 0

        $sequence_8 = { 0fbe8030c24000 83e00f 33f6 eb04 33f6 33c0 0fbe84c150c24000 }
            // n = 7, score = 100
            //   0fbe8030c24000       | movsx               eax, byte ptr [eax + 0x40c230]
            //   83e00f               | and                 eax, 0xf
            //   33f6                 | xor                 esi, esi
            //   eb04                 | jmp                 6
            //   33f6                 | xor                 esi, esi
            //   33c0                 | xor                 eax, eax
            //   0fbe84c150c24000     | movsx               eax, byte ptr [ecx + eax*8 + 0x40c250]

        $sequence_9 = { 57 ffd3 85c0 0f847e000000 57 }
            // n = 5, score = 100
            //   57                   | push                edi
            //   ffd3                 | call                ebx
            //   85c0                 | test                eax, eax
            //   0f847e000000         | je                  0x84
            //   57                   | push                edi

    condition:
        7 of them and filesize < 24846336
}