rule win_winsloader_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-03-29"
        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 = "20230328"
        malpedia_hash = "9d2d75cef573c1c2d861f5197df8f563b05a305d"
        malpedia_version = "20230407"
        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 = { a4 8dbbdf000000 b911000000 be???????? f3a5 83c40c }
            // n = 6, score = 200
            //   a4                   | movsb               byte ptr es:[edi], byte ptr [esi]
            //   8dbbdf000000         | lea                 edi, [ebx + 0xdf]
            //   b911000000           | mov                 ecx, 0x11
            //   be????????           |                     
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   83c40c               | add                 esp, 0xc

        $sequence_1 = { 68???????? 51 e8???????? 83c40c 03f7 b8???????? 66c78435fcfbffff9001 }
            // n = 7, score = 200
            //   68????????           |                     
            //   51                   | push                ecx
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   03f7                 | add                 esi, edi
            //   b8????????           |                     
            //   66c78435fcfbffff9001     | mov    word ptr [ebp + esi - 0x404], 0x190

        $sequence_2 = { 8990020e0000 8b0d???????? 8988060e0000 8b15???????? 89900a0e0000 668b0d???????? 6689880e0e0000 }
            // n = 7, score = 200
            //   8990020e0000         | mov                 dword ptr [eax + 0xe02], edx
            //   8b0d????????         |                     
            //   8988060e0000         | mov                 dword ptr [eax + 0xe06], ecx
            //   8b15????????         |                     
            //   89900a0e0000         | mov                 dword ptr [eax + 0xe0a], edx
            //   668b0d????????       |                     
            //   6689880e0e0000       | mov                 word ptr [eax + 0xe0e], cx

        $sequence_3 = { 83c40c a4 ffd0 5b 5f 5e }
            // n = 6, score = 200
            //   83c40c               | add                 esp, 0xc
            //   a4                   | movsb               byte ptr es:[edi], byte ptr [esi]
            //   ffd0                 | call                eax
            //   5b                   | pop                 ebx
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi

        $sequence_4 = { a1???????? 898c1dfefbffff 8b0d???????? 89941d02fcffff }
            // n = 4, score = 200
            //   a1????????           |                     
            //   898c1dfefbffff       | mov                 dword ptr [ebp + ebx - 0x402], ecx
            //   8b0d????????         |                     
            //   89941d02fcffff       | mov                 dword ptr [ebp + ebx - 0x3fe], edx

        $sequence_5 = { 8bd8 ff15???????? 53 e8???????? 8bf0 83c404 }
            // n = 6, score = 200
            //   8bd8                 | mov                 ebx, eax
            //   ff15????????         |                     
            //   53                   | push                ebx
            //   e8????????           |                     
            //   8bf0                 | mov                 esi, eax
            //   83c404               | add                 esp, 4

        $sequence_6 = { 83c404 85f6 750e 57 ff15???????? 33c0 }
            // n = 6, score = 200
            //   83c404               | add                 esp, 4
            //   85f6                 | test                esi, esi
            //   750e                 | jne                 0x10
            //   57                   | push                edi
            //   ff15????????         |                     
            //   33c0                 | xor                 eax, eax

        $sequence_7 = { 68???????? 8d5c3304 e8???????? 8b0d???????? 8b15???????? 6689841dfcfbffff a1???????? }
            // n = 7, score = 200
            //   68????????           |                     
            //   8d5c3304             | lea                 ebx, [ebx + esi + 4]
            //   e8????????           |                     
            //   8b0d????????         |                     
            //   8b15????????         |                     
            //   6689841dfcfbffff     | mov                 word ptr [ebp + ebx - 0x404], ax
            //   a1????????           |                     

        $sequence_8 = { 83c40c 6800040000 8d8dfcf7ffff 51 }
            // n = 4, score = 200
            //   83c40c               | add                 esp, 0xc
            //   6800040000           | push                0x400
            //   8d8dfcf7ffff         | lea                 ecx, [ebp - 0x804]
            //   51                   | push                ecx

        $sequence_9 = { 05fa0d0000 8985ecf3ffff 8b8de4f3ffff 038decf3ffff 8b15???????? 8911 a1???????? }
            // n = 7, score = 100
            //   05fa0d0000           | add                 eax, 0xdfa
            //   8985ecf3ffff         | mov                 dword ptr [ebp - 0xc14], eax
            //   8b8de4f3ffff         | mov                 ecx, dword ptr [ebp - 0xc1c]
            //   038decf3ffff         | add                 ecx, dword ptr [ebp - 0xc14]
            //   8b15????????         |                     
            //   8911                 | mov                 dword ptr [ecx], edx
            //   a1????????           |                     

        $sequence_10 = { 83c201 8995f8f3ffff 0fb685f7f3ffff 83c001 }
            // n = 4, score = 100
            //   83c201               | add                 edx, 1
            //   8995f8f3ffff         | mov                 dword ptr [ebp - 0xc08], edx
            //   0fb685f7f3ffff       | movzx               eax, byte ptr [ebp - 0xc09]
            //   83c001               | add                 eax, 1

        $sequence_11 = { e8???????? 83c40c 0fb695f7f3ffff 8b85f8f3ffff }
            // n = 4, score = 100
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   0fb695f7f3ffff       | movzx               edx, byte ptr [ebp - 0xc09]
            //   8b85f8f3ffff         | mov                 eax, dword ptr [ebp - 0xc08]

        $sequence_12 = { 0f8487660000 c3 833d????????ff 7503 33c0 c3 }
            // n = 6, score = 100
            //   0f8487660000         | je                  0x668d
            //   c3                   | ret                 
            //   833d????????ff       |                     
            //   7503                 | jne                 5
            //   33c0                 | xor                 eax, eax
            //   c3                   | ret                 

        $sequence_13 = { c7860008000000000000 c7860408000000000000 c7860808000000000000 c7860c08000000000000 }
            // n = 4, score = 100
            //   c7860008000000000000     | mov    dword ptr [esi + 0x800], 0
            //   c7860408000000000000     | mov    dword ptr [esi + 0x804], 0
            //   c7860808000000000000     | mov    dword ptr [esi + 0x808], 0
            //   c7860c08000000000000     | mov    dword ptr [esi + 0x80c], 0

        $sequence_14 = { ff7004 ff30 e8???????? 83c41c 5d c3 3b0d???????? }
            // n = 7, score = 100
            //   ff7004               | push                dword ptr [eax + 4]
            //   ff30                 | push                dword ptr [eax]
            //   e8????????           |                     
            //   83c41c               | add                 esp, 0x1c
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   3b0d????????         |                     

        $sequence_15 = { 0fb785f0f3ffff 50 68???????? 8b8df8f3ffff 8d940dfcfbffff 52 }
            // n = 6, score = 100
            //   0fb785f0f3ffff       | movzx               eax, word ptr [ebp - 0xc10]
            //   50                   | push                eax
            //   68????????           |                     
            //   8b8df8f3ffff         | mov                 ecx, dword ptr [ebp - 0xc08]
            //   8d940dfcfbffff       | lea                 edx, [ebp + ecx - 0x404]
            //   52                   | push                edx

    condition:
        7 of them and filesize < 270336
}