rule win_varenyky_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        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 = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        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 = { 6803010000 8d4c244d 6a00 51 c644245400 }
            // n = 5, score = 100
            //   6803010000           | push                0x103
            //   8d4c244d             | lea                 ecx, [esp + 0x4d]
            //   6a00                 | push                0
            //   51                   | push                ecx
            //   c644245400           | mov                 byte ptr [esp + 0x54], 0

        $sequence_1 = { 6803010000 8d842485020000 53 50 889c248c020000 e8???????? }
            // n = 6, score = 100
            //   6803010000           | push                0x103
            //   8d842485020000       | lea                 eax, [esp + 0x285]
            //   53                   | push                ebx
            //   50                   | push                eax
            //   889c248c020000       | mov                 byte ptr [esp + 0x28c], bl
            //   e8????????           |                     

        $sequence_2 = { 399c24ec0a0000 7417 8d8c24d0000000 51 68???????? 8d9424e0010000 }
            // n = 6, score = 100
            //   399c24ec0a0000       | cmp                 dword ptr [esp + 0xaec], ebx
            //   7417                 | je                  0x19
            //   8d8c24d0000000       | lea                 ecx, [esp + 0xd0]
            //   51                   | push                ecx
            //   68????????           |                     
            //   8d9424e0010000       | lea                 edx, [esp + 0x1e0]

        $sequence_3 = { 8b03 50 55 ffd6 85c0 0f8eb5010000 8b3d???????? }
            // n = 7, score = 100
            //   8b03                 | mov                 eax, dword ptr [ebx]
            //   50                   | push                eax
            //   55                   | push                ebp
            //   ffd6                 | call                esi
            //   85c0                 | test                eax, eax
            //   0f8eb5010000         | jle                 0x1bb
            //   8b3d????????         |                     

        $sequence_4 = { 8945e4 83f805 7d10 668b4c4310 66890c45ac0bfd00 }
            // n = 5, score = 100
            //   8945e4               | mov                 dword ptr [ebp - 0x1c], eax
            //   83f805               | cmp                 eax, 5
            //   7d10                 | jge                 0x12
            //   668b4c4310           | mov                 cx, word ptr [ebx + eax*2 + 0x10]
            //   66890c45ac0bfd00     | mov                 word ptr [eax*2 + 0xfd0bac], cx

        $sequence_5 = { 56 e8???????? 8bc6 c1f805 8b0485401efd00 83e61f }
            // n = 6, score = 100
            //   56                   | push                esi
            //   e8????????           |                     
            //   8bc6                 | mov                 eax, esi
            //   c1f805               | sar                 eax, 5
            //   8b0485401efd00       | mov                 eax, dword ptr [eax*4 + 0xfd1e40]
            //   83e61f               | and                 esi, 0x1f

        $sequence_6 = { 5e 33cc e8???????? 81c47c020000 c3 be???????? 8bd7 }
            // n = 7, score = 100
            //   5e                   | pop                 esi
            //   33cc                 | xor                 ecx, esp
            //   e8????????           |                     
            //   81c47c020000         | add                 esp, 0x27c
            //   c3                   | ret                 
            //   be????????           |                     
            //   8bd7                 | mov                 edx, edi

        $sequence_7 = { 50 68???????? 8d8c24e0010000 51 e8???????? }
            // n = 5, score = 100
            //   50                   | push                eax
            //   68????????           |                     
            //   8d8c24e0010000       | lea                 ecx, [esp + 0x1e0]
            //   51                   | push                ecx
            //   e8????????           |                     

        $sequence_8 = { 6830750000 50 ff15???????? 8b4c2410 51 }
            // n = 5, score = 100
            //   6830750000           | push                0x7530
            //   50                   | push                eax
            //   ff15????????         |                     
            //   8b4c2410             | mov                 ecx, dword ptr [esp + 0x10]
            //   51                   | push                ecx

        $sequence_9 = { 7e09 8bce e8???????? eb0b 6860ea0000 }
            // n = 5, score = 100
            //   7e09                 | jle                 0xb
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   eb0b                 | jmp                 0xd
            //   6860ea0000           | push                0xea60

    condition:
        7 of them and filesize < 24846336
}