rule win_winsloader_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        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 = "20220405"
        malpedia_hash = "ecd38294bd47d5589be5cd5490dc8bb4804afc2a"
        malpedia_version = "20220411"
        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 = { 6a00 57 8bd8 ff15???????? 53 e8???????? }
            // n = 6, score = 200
            //   6a00                 | push                0
            //   57                   | push                edi
            //   8bd8                 | mov                 ebx, eax
            //   ff15????????         |                     
            //   53                   | push                ebx
            //   e8????????           |                     

        $sequence_1 = { f3a5 83c40c a4 ffd0 5b }
            // n = 5, score = 200
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   83c40c               | add                 esp, 0xc
            //   a4                   | movsb               byte ptr es:[edi], byte ptr [esi]
            //   ffd0                 | call                eax
            //   5b                   | pop                 ebx

        $sequence_2 = { 8bf8 83ffff 742e 6a00 }
            // n = 4, score = 200
            //   8bf8                 | mov                 edi, eax
            //   83ffff               | cmp                 edi, -1
            //   742e                 | je                  0x30
            //   6a00                 | push                0

        $sequence_3 = { 56 e8???????? 83c40c 6a00 8d45d8 50 }
            // n = 6, score = 200
            //   56                   | push                esi
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   6a00                 | push                0
            //   8d45d8               | lea                 eax, dword ptr [ebp - 0x28]
            //   50                   | push                eax

        $sequence_4 = { 51 8d943501fcffff 68???????? 52 }
            // n = 4, score = 200
            //   51                   | push                ecx
            //   8d943501fcffff       | lea                 edx, dword ptr [ebp + esi - 0x3ff]
            //   68????????           |                     
            //   52                   | push                edx

        $sequence_5 = { 81f901100000 72f0 8bd8 c745fcffffffff }
            // n = 4, score = 200
            //   81f901100000         | cmp                 ecx, 0x1001
            //   72f0                 | jb                  0xfffffff2
            //   8bd8                 | mov                 ebx, eax
            //   c745fcffffffff       | mov                 dword ptr [ebp - 4], 0xffffffff

        $sequence_6 = { 0fb6f0 8d5601 52 88841dfefbffff 8d841dfffbffff 68???????? 50 }
            // n = 7, score = 200
            //   0fb6f0               | movzx               esi, al
            //   8d5601               | lea                 edx, dword ptr [esi + 1]
            //   52                   | push                edx
            //   88841dfefbffff       | mov                 byte ptr [ebp + ebx - 0x402], al
            //   8d841dfffbffff       | lea                 eax, dword ptr [ebp + ebx - 0x401]
            //   68????????           |                     
            //   50                   | push                eax

        $sequence_7 = { 83c40c 6800040000 8d8dfcf7ffff 51 }
            // n = 4, score = 200
            //   83c40c               | add                 esp, 0xc
            //   6800040000           | push                0x400
            //   8d8dfcf7ffff         | lea                 ecx, dword ptr [ebp - 0x804]
            //   51                   | push                ecx

        $sequence_8 = { 8bf0 83c404 85f6 750e 57 ff15???????? 33c0 }
            // n = 7, score = 200
            //   8bf0                 | mov                 esi, eax
            //   83c404               | add                 esp, 4
            //   85f6                 | test                esi, esi
            //   750e                 | jne                 0x10
            //   57                   | push                edi
            //   ff15????????         |                     
            //   33c0                 | xor                 eax, eax

        $sequence_9 = { ff15???????? 8b04bdc0c00110 834c0318ff 33c0 eb16 e8???????? }
            // n = 6, score = 100
            //   ff15????????         |                     
            //   8b04bdc0c00110       | mov                 eax, dword ptr [edi*4 + 0x1001c0c0]
            //   834c0318ff           | or                  dword ptr [ebx + eax + 0x18], 0xffffffff
            //   33c0                 | xor                 eax, eax
            //   eb16                 | jmp                 0x18
            //   e8????????           |                     

        $sequence_10 = { 6690 8a040b 8d4901 8841ff 83ea01 75f2 }
            // n = 6, score = 100
            //   6690                 | nop                 
            //   8a040b               | mov                 al, byte ptr [ebx + ecx]
            //   8d4901               | lea                 ecx, dword ptr [ecx + 1]
            //   8841ff               | mov                 byte ptr [ecx - 1], al
            //   83ea01               | sub                 edx, 1
            //   75f2                 | jne                 0xfffffff4

        $sequence_11 = { 668985e8f3ffff 8b8df8f3ffff 668b95e8f3ffff 6689940dfcfbffff 8b85f8f3ffff }
            // n = 5, score = 100
            //   668985e8f3ffff       | mov                 word ptr [ebp - 0xc18], ax
            //   8b8df8f3ffff         | mov                 ecx, dword ptr [ebp - 0xc08]
            //   668b95e8f3ffff       | mov                 dx, word ptr [ebp - 0xc18]
            //   6689940dfcfbffff     | mov                 word ptr [ebp + ecx - 0x404], dx
            //   8b85f8f3ffff         | mov                 eax, dword ptr [ebp - 0xc08]

        $sequence_12 = { 6bf030 03348dc0c00110 837e18ff 740c 837e18fe 7406 }
            // n = 6, score = 100
            //   6bf030               | imul                esi, eax, 0x30
            //   03348dc0c00110       | add                 esi, dword ptr [ecx*4 + 0x1001c0c0]
            //   837e18ff             | cmp                 dword ptr [esi + 0x18], -1
            //   740c                 | je                  0xe
            //   837e18fe             | cmp                 dword ptr [esi + 0x18], -2
            //   7406                 | je                  8

        $sequence_13 = { 741c 8b74241c 8bcf 2bf7 }
            // n = 4, score = 100
            //   741c                 | je                  0x1e
            //   8b74241c             | mov                 esi, dword ptr [esp + 0x1c]
            //   8bcf                 | mov                 ecx, edi
            //   2bf7                 | sub                 esi, edi

        $sequence_14 = { 8d0c48 894dfc 80fb08 750f 32db 46 889f10800000 }
            // n = 7, score = 100
            //   8d0c48               | lea                 ecx, dword ptr [eax + ecx*2]
            //   894dfc               | mov                 dword ptr [ebp - 4], ecx
            //   80fb08               | cmp                 bl, 8
            //   750f                 | jne                 0x11
            //   32db                 | xor                 bl, bl
            //   46                   | inc                 esi
            //   889f10800000         | mov                 byte ptr [edi + 0x8010], bl

        $sequence_15 = { 8bd6 83e03f c1fa06 6bc830 8b0495c0c00110 f644082801 }
            // n = 6, score = 100
            //   8bd6                 | mov                 edx, esi
            //   83e03f               | and                 eax, 0x3f
            //   c1fa06               | sar                 edx, 6
            //   6bc830               | imul                ecx, eax, 0x30
            //   8b0495c0c00110       | mov                 eax, dword ptr [edx*4 + 0x1001c0c0]
            //   f644082801           | test                byte ptr [eax + ecx + 0x28], 1

    condition:
        7 of them and filesize < 270336
}