rule win_downeks_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.downeks."
        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.downeks"
        malpedia_rule_date = "20260916"
        malpedia_hash = "53a643781c18e08f4a50949af60172d837a0b6f6"
        malpedia_version = "20260917"
        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 = { 89860c010000 85c0 7444 c7865886000001000000 eb72 8b860c010000 85c0 }
            // n = 7, score = 200
            //   89860c010000         | mov                 dword ptr [esi + 0x10c], eax
            //   85c0                 | test                eax, eax
            //   7444                 | je                  0x46
            //   c7865886000001000000     | mov    dword ptr [esi + 0x8658], 1
            //   eb72                 | jmp                 0x74
            //   8b860c010000         | mov                 eax, dword ptr [esi + 0x10c]
            //   85c0                 | test                eax, eax

        $sequence_1 = { b8502c0804 5d c3 b8182c0804 5d c3 b8042c0804 }
            // n = 7, score = 200
            //   b8502c0804           | mov                 eax, 0x4082c50
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   b8182c0804           | mov                 eax, 0x4082c18
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   b8042c0804           | mov                 eax, 0x4082c04

        $sequence_2 = { c7868c00000003000000 e9???????? c7868c00000002000000 e9???????? 8b4668 6a0e 50 }
            // n = 7, score = 200
            //   c7868c00000003000000     | mov    dword ptr [esi + 0x8c], 3
            //   e9????????           |                     
            //   c7868c00000002000000     | mov    dword ptr [esi + 0x8c], 2
            //   e9????????           |                     
            //   8b4668               | mov                 eax, dword ptr [esi + 0x68]
            //   6a0e                 | push                0xe
            //   50                   | push                eax

        $sequence_3 = { a1???????? 33c5 8945fc 8b06 8b80c0860000 803800 7523 }
            // n = 7, score = 200
            //   a1????????           |                     
            //   33c5                 | xor                 eax, ebp
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   8b06                 | mov                 eax, dword ptr [esi]
            //   8b80c0860000         | mov                 eax, dword ptr [eax + 0x86c0]
            //   803800               | cmp                 byte ptr [eax], 0
            //   7523                 | jne                 0x25

        $sequence_4 = { 8d770c e8???????? 8b5f0c 83c404 85db 0f8411020000 8bc3 }
            // n = 7, score = 200
            //   8d770c               | lea                 esi, [edi + 0xc]
            //   e8????????           |                     
            //   8b5f0c               | mov                 ebx, dword ptr [edi + 0xc]
            //   83c404               | add                 esp, 4
            //   85db                 | test                ebx, ebx
            //   0f8411020000         | je                  0x217
            //   8bc3                 | mov                 eax, ebx

        $sequence_5 = { dd18 e9???????? c745d803000000 c745dc38990804 e9???????? 81c118fcffff 83f90c }
            // n = 7, score = 200
            //   dd18                 | fstp                qword ptr [eax]
            //   e9????????           |                     
            //   c745d803000000       | mov                 dword ptr [ebp - 0x28], 3
            //   c745dc38990804       | mov                 dword ptr [ebp - 0x24], 0x4089938
            //   e9????????           |                     
            //   81c118fcffff         | add                 ecx, 0xfffffc18
            //   83f90c               | cmp                 ecx, 0xc

        $sequence_6 = { 0f8c990a0000 8d41e0 6683f858 770f 0fb7c1 0fbe8010970804 83e00f }
            // n = 7, score = 200
            //   0f8c990a0000         | jl                  0xa9f
            //   8d41e0               | lea                 eax, [ecx - 0x20]
            //   6683f858             | cmp                 ax, 0x58
            //   770f                 | ja                  0x11
            //   0fb7c1               | movzx               eax, cx
            //   0fbe8010970804       | movsx               eax, byte ptr [eax + 0x4089710]
            //   83e00f               | and                 eax, 0xf

        $sequence_7 = { b9b8270904 2bc1 50 51 8d45bc 50 8bc6 }
            // n = 7, score = 200
            //   b9b8270904           | mov                 ecx, 0x40927b8
            //   2bc1                 | sub                 eax, ecx
            //   50                   | push                eax
            //   51                   | push                ecx
            //   8d45bc               | lea                 eax, [ebp - 0x44]
            //   50                   | push                eax
            //   8bc6                 | mov                 eax, esi

        $sequence_8 = { d1f8 50 8d85d8f9ffff 50 8d8dbcf9ffff 51 e8???????? }
            // n = 7, score = 200
            //   d1f8                 | sar                 eax, 1
            //   50                   | push                eax
            //   8d85d8f9ffff         | lea                 eax, [ebp - 0x628]
            //   50                   | push                eax
            //   8d8dbcf9ffff         | lea                 ecx, [ebp - 0x644]
            //   51                   | push                ecx
            //   e8????????           |                     

        $sequence_9 = { c1cf06 33cf 038d48ffffff 8b7df0 337dec 23fa 337df0 }
            // n = 7, score = 200
            //   c1cf06               | ror                 edi, 6
            //   33cf                 | xor                 ecx, edi
            //   038d48ffffff         | add                 ecx, dword ptr [ebp - 0xb8]
            //   8b7df0               | mov                 edi, dword ptr [ebp - 0x10]
            //   337dec               | xor                 edi, dword ptr [ebp - 0x14]
            //   23fa                 | and                 edi, edx
            //   337df0               | xor                 edi, dword ptr [ebp - 0x10]

    condition:
        7 of them and filesize < 1318912
}