rule win_downeks_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        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 = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { c1cf07 33cf 8bbd38ffffff c1ef03 33cf 03cb 038d34ffffff }
            // n = 7, score = 200
            //   c1cf07               | ror                 edi, 7
            //   33cf                 | xor                 ecx, edi
            //   8bbd38ffffff         | mov                 edi, dword ptr [ebp - 0xc8]
            //   c1ef03               | shr                 edi, 3
            //   33cf                 | xor                 ecx, edi
            //   03cb                 | add                 ecx, ebx
            //   038d34ffffff         | add                 ecx, dword ptr [ebp - 0xcc]

        $sequence_1 = { e8???????? 6aff 6a00 8d8db0fdffff 51 e8???????? 6a04 }
            // n = 7, score = 200
            //   e8????????           |                     
            //   6aff                 | push                -1
            //   6a00                 | push                0
            //   8d8db0fdffff         | lea                 ecx, [ebp - 0x250]
            //   51                   | push                ecx
            //   e8????????           |                     
            //   6a04                 | push                4

        $sequence_2 = { 0bd7 0fb67804 89548dbc 0fb65005 c1e208 0bd7 0fb67803 }
            // n = 7, score = 200
            //   0bd7                 | or                  edx, edi
            //   0fb67804             | movzx               edi, byte ptr [eax + 4]
            //   89548dbc             | mov                 dword ptr [ebp + ecx*4 - 0x44], edx
            //   0fb65005             | movzx               edx, byte ptr [eax + 5]
            //   c1e208               | shl                 edx, 8
            //   0bd7                 | or                  edx, edi
            //   0fb67803             | movzx               edi, byte ptr [eax + 3]

        $sequence_3 = { e8???????? 83c418 eb1c 8b96f4860000 8b8ed0860000 52 50 }
            // n = 7, score = 200
            //   e8????????           |                     
            //   83c418               | add                 esp, 0x18
            //   eb1c                 | jmp                 0x1e
            //   8b96f4860000         | mov                 edx, dword ptr [esi + 0x86f4]
            //   8b8ed0860000         | mov                 ecx, dword ptr [esi + 0x86d0]
            //   52                   | push                edx
            //   50                   | push                eax

        $sequence_4 = { 8d5801 8a08 40 84c9 75f9 2bc3 2bc2 }
            // n = 7, score = 200
            //   8d5801               | lea                 ebx, [eax + 1]
            //   8a08                 | mov                 cl, byte ptr [eax]
            //   40                   | inc                 eax
            //   84c9                 | test                cl, cl
            //   75f9                 | jne                 0xfffffffb
            //   2bc3                 | sub                 eax, ebx
            //   2bc2                 | sub                 eax, edx

        $sequence_5 = { c745fc01000000 84c9 7507 ba04000000 eb66 8b5d14 8b7d10 }
            // n = 7, score = 200
            //   c745fc01000000       | mov                 dword ptr [ebp - 4], 1
            //   84c9                 | test                cl, cl
            //   7507                 | jne                 9
            //   ba04000000           | mov                 edx, 4
            //   eb66                 | jmp                 0x68
            //   8b5d14               | mov                 ebx, dword ptr [ebp + 0x14]
            //   8b7d10               | mov                 edi, dword ptr [ebp + 0x10]

        $sequence_6 = { 8d9b00000000 40 803800 75fa b9dc2b0904 2bc1 50 }
            // n = 7, score = 200
            //   8d9b00000000         | lea                 ebx, [ebx]
            //   40                   | inc                 eax
            //   803800               | cmp                 byte ptr [eax], 0
            //   75fa                 | jne                 0xfffffffc
            //   b9dc2b0904           | mov                 ecx, 0x4092bdc
            //   2bc1                 | sub                 eax, ecx
            //   50                   | push                eax

        $sequence_7 = { 85f6 74a8 8bc3 56 50 e8???????? 56 }
            // n = 7, score = 200
            //   85f6                 | test                esi, esi
            //   74a8                 | je                  0xffffffaa
            //   8bc3                 | mov                 eax, ebx
            //   56                   | push                esi
            //   50                   | push                eax
            //   e8????????           |                     
            //   56                   | push                esi

        $sequence_8 = { 8bcf e8???????? 8b0f 8d04b6 8b7704 8d1cc1 8975f0 }
            // n = 7, score = 200
            //   8bcf                 | mov                 ecx, edi
            //   e8????????           |                     
            //   8b0f                 | mov                 ecx, dword ptr [edi]
            //   8d04b6               | lea                 eax, [esi + esi*4]
            //   8b7704               | mov                 esi, dword ptr [edi + 4]
            //   8d1cc1               | lea                 ebx, [ecx + eax*8]
            //   8975f0               | mov                 dword ptr [ebp - 0x10], esi

        $sequence_9 = { 03c9 03c0 03c9 52 e8???????? 8906 897e08 }
            // n = 7, score = 200
            //   03c9                 | add                 ecx, ecx
            //   03c0                 | add                 eax, eax
            //   03c9                 | add                 ecx, ecx
            //   52                   | push                edx
            //   e8????????           |                     
            //   8906                 | mov                 dword ptr [esi], eax
            //   897e08               | mov                 dword ptr [esi + 8], edi

    condition:
        7 of them and filesize < 1318912
}