rule win_winsloader_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.winsloader."
        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.winsloader"
        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 = { 8bf0 56 668985fefbffff 8d8500fcffff }
            // n = 4, score = 200
            //   8bf0                 | mov                 esi, eax
            //   56                   | push                esi
            //   668985fefbffff       | mov                 word ptr [ebp - 0x402], ax
            //   8d8500fcffff         | lea                 eax, [ebp - 0x400]

        $sequence_1 = { b8???????? 8d7801 8a10 40 84d2 }
            // n = 5, score = 200
            //   b8????????           |                     
            //   8d7801               | lea                 edi, [eax + 1]
            //   8a10                 | mov                 dl, byte ptr [eax]
            //   40                   | inc                 eax
            //   84d2                 | test                dl, dl

        $sequence_2 = { 83c40c 6800040000 8d8dfcf7ffff 51 }
            // n = 4, score = 200
            //   83c40c               | add                 esp, 0xc
            //   6800040000           | push                0x400
            //   8d8dfcf7ffff         | lea                 ecx, [ebp - 0x804]
            //   51                   | push                ecx

        $sequence_3 = { 81f901100000 72f0 8bd8 c745fcffffffff 85db 7516 56 }
            // n = 7, score = 200
            //   81f901100000         | cmp                 ecx, 0x1001
            //   72f0                 | jb                  0xfffffff2
            //   8bd8                 | mov                 ebx, eax
            //   c745fcffffffff       | mov                 dword ptr [ebp - 4], 0xffffffff
            //   85db                 | test                ebx, ebx
            //   7516                 | jne                 0x18
            //   56                   | push                esi

        $sequence_4 = { 2bc2 8d1439 8d44020c 0fb6f9 66898435fefbffff 888c3500fcffff 8d4f01 }
            // n = 7, score = 200
            //   2bc2                 | sub                 eax, edx
            //   8d1439               | lea                 edx, [ecx + edi]
            //   8d44020c             | lea                 eax, [edx + eax + 0xc]
            //   0fb6f9               | movzx               edi, cl
            //   66898435fefbffff     | mov                 word ptr [ebp + esi - 0x402], ax
            //   888c3500fcffff       | mov                 byte ptr [ebp + esi - 0x400], cl
            //   8d4f01               | lea                 ecx, [edi + 1]

        $sequence_5 = { e8???????? 8b0d???????? 8b15???????? 6689841dfcfbffff a1???????? 898c1dfefbffff 8b0d???????? }
            // n = 7, score = 200
            //   e8????????           |                     
            //   8b0d????????         |                     
            //   8b15????????         |                     
            //   6689841dfcfbffff     | mov                 word ptr [ebp + ebx - 0x404], ax
            //   a1????????           |                     
            //   898c1dfefbffff       | mov                 dword ptr [ebp + ebx - 0x402], ecx
            //   8b0d????????         |                     

        $sequence_6 = { 68ff030000 8d95fdfbffff 6a00 52 e8???????? }
            // n = 5, score = 200
            //   68ff030000           | push                0x3ff
            //   8d95fdfbffff         | lea                 edx, [ebp - 0x403]
            //   6a00                 | push                0
            //   52                   | push                edx
            //   e8????????           |                     

        $sequence_7 = { 6a00 56 e8???????? 83c40c 6a00 8d45d8 }
            // n = 6, score = 200
            //   6a00                 | push                0
            //   56                   | push                esi
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   6a00                 | push                0
            //   8d45d8               | lea                 eax, [ebp - 0x28]

        $sequence_8 = { 33c0 e9???????? 57 8d45dc 50 }
            // n = 5, score = 200
            //   33c0                 | xor                 eax, eax
            //   e9????????           |                     
            //   57                   | push                edi
            //   8d45dc               | lea                 eax, [ebp - 0x24]
            //   50                   | push                eax

        $sequence_9 = { 8bcf 50 8d4610 50 e8???????? 8b4dc8 8bd0 }
            // n = 7, score = 100
            //   8bcf                 | mov                 ecx, edi
            //   50                   | push                eax
            //   8d4610               | lea                 eax, [esi + 0x10]
            //   50                   | push                eax
            //   e8????????           |                     
            //   8b4dc8               | mov                 ecx, dword ptr [ebp - 0x38]
            //   8bd0                 | mov                 edx, eax

        $sequence_10 = { 68???????? e8???????? 83c404 668985e8f3ffff 8b8df8f3ffff 668b95e8f3ffff }
            // n = 6, score = 100
            //   68????????           |                     
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   668985e8f3ffff       | mov                 word ptr [ebp - 0xc18], ax
            //   8b8df8f3ffff         | mov                 ecx, dword ptr [ebp - 0xc08]
            //   668b95e8f3ffff       | mov                 dx, word ptr [ebp - 0xc18]

        $sequence_11 = { 83e03f 6bc830 8b0495c0c00110 f644082801 7421 }
            // n = 5, score = 100
            //   83e03f               | and                 eax, 0x3f
            //   6bc830               | imul                ecx, eax, 0x30
            //   8b0495c0c00110       | mov                 eax, dword ptr [edx*4 + 0x1001c0c0]
            //   f644082801           | test                byte ptr [eax + ecx + 0x28], 1
            //   7421                 | je                  0x23

        $sequence_12 = { 56 50 0f1145e0 e8???????? 6a10 }
            // n = 5, score = 100
            //   56                   | push                esi
            //   50                   | push                eax
            //   0f1145e0             | movups              xmmword ptr [ebp - 0x20], xmm0
            //   e8????????           |                     
            //   6a10                 | push                0x10

        $sequence_13 = { 8bfe 83e03f c1ff06 6bd830 8b04bdc0c00110 }
            // n = 5, score = 100
            //   8bfe                 | mov                 edi, esi
            //   83e03f               | and                 eax, 0x3f
            //   c1ff06               | sar                 edi, 6
            //   6bd830               | imul                ebx, eax, 0x30
            //   8b04bdc0c00110       | mov                 eax, dword ptr [edi*4 + 0x1001c0c0]

        $sequence_14 = { 85f6 7479 ff75cc 6a00 56 e8???????? ff75cc }
            // n = 7, score = 100
            //   85f6                 | test                esi, esi
            //   7479                 | je                  0x7b
            //   ff75cc               | push                dword ptr [ebp - 0x34]
            //   6a00                 | push                0
            //   56                   | push                esi
            //   e8????????           |                     
            //   ff75cc               | push                dword ptr [ebp - 0x34]

        $sequence_15 = { c745e0547c0110 e9???????? c745dc03000000 c745e0607c0110 e9???????? 83e80f 7451 }
            // n = 7, score = 100
            //   c745e0547c0110       | mov                 dword ptr [ebp - 0x20], 0x10017c54
            //   e9????????           |                     
            //   c745dc03000000       | mov                 dword ptr [ebp - 0x24], 3
            //   c745e0607c0110       | mov                 dword ptr [ebp - 0x20], 0x10017c60
            //   e9????????           |                     
            //   83e80f               | sub                 eax, 0xf
            //   7451                 | je                  0x53

    condition:
        7 of them and filesize < 270336
}