rule win_vskimmer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.vskimmer."
        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.vskimmer"
        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 = { 8b1d???????? be???????? 85c0 740c 6a00 56 56 }
            // n = 7, score = 100
            //   8b1d????????         |                     
            //   be????????           |                     
            //   85c0                 | test                eax, eax
            //   740c                 | je                  0xe
            //   6a00                 | push                0
            //   56                   | push                esi
            //   56                   | push                esi

        $sequence_1 = { 7524 8b4728 85c0 7421 8b4dfc 81c12c020000 }
            // n = 6, score = 100
            //   7524                 | jne                 0x26
            //   8b4728               | mov                 eax, dword ptr [edi + 0x28]
            //   85c0                 | test                eax, eax
            //   7421                 | je                  0x23
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]
            //   81c12c020000         | add                 ecx, 0x22c

        $sequence_2 = { 8d45b8 897e14 895e10 50 8bce c745fc02000000 881e }
            // n = 7, score = 100
            //   8d45b8               | lea                 eax, [ebp - 0x48]
            //   897e14               | mov                 dword ptr [esi + 0x14], edi
            //   895e10               | mov                 dword ptr [esi + 0x10], ebx
            //   50                   | push                eax
            //   8bce                 | mov                 ecx, esi
            //   c745fc02000000       | mov                 dword ptr [ebp - 4], 2
            //   881e                 | mov                 byte ptr [esi], bl

        $sequence_3 = { 85c0 7443 8d85f8feffff 68???????? 50 }
            // n = 5, score = 100
            //   85c0                 | test                eax, eax
            //   7443                 | je                  0x45
            //   8d85f8feffff         | lea                 eax, [ebp - 0x108]
            //   68????????           |                     
            //   50                   | push                eax

        $sequence_4 = { 770e 6a0d 58 5d c3 8b04cd74494200 }
            // n = 6, score = 100
            //   770e                 | ja                  0x10
            //   6a0d                 | push                0xd
            //   58                   | pop                 eax
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   8b04cd74494200       | mov                 eax, dword ptr [ecx*8 + 0x424974]

        $sequence_5 = { 32c0 5d c20400 55 8bec 807d0861 7504 }
            // n = 7, score = 100
            //   32c0                 | xor                 al, al
            //   5d                   | pop                 ebp
            //   c20400               | ret                 4
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   807d0861             | cmp                 byte ptr [ebp + 8], 0x61
            //   7504                 | jne                 6

        $sequence_6 = { e8???????? 6803010000 8d85edfeffff 57 50 }
            // n = 5, score = 100
            //   e8????????           |                     
            //   6803010000           | push                0x103
            //   8d85edfeffff         | lea                 eax, [ebp - 0x113]
            //   57                   | push                edi
            //   50                   | push                eax

        $sequence_7 = { e8???????? 33f6 56 e8???????? 83c420 56 6a01 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   33f6                 | xor                 esi, esi
            //   56                   | push                esi
            //   e8????????           |                     
            //   83c420               | add                 esp, 0x20
            //   56                   | push                esi
            //   6a01                 | push                1

        $sequence_8 = { e8???????? 57 53 8d8dc8f6ffff e8???????? 57 }
            // n = 6, score = 100
            //   e8????????           |                     
            //   57                   | push                edi
            //   53                   | push                ebx
            //   8d8dc8f6ffff         | lea                 ecx, [ebp - 0x938]
            //   e8????????           |                     
            //   57                   | push                edi

        $sequence_9 = { ff7508 ff0d???????? ff15???????? 8b0d???????? 89048de0654200 }
            // n = 5, score = 100
            //   ff7508               | push                dword ptr [ebp + 8]
            //   ff0d????????         |                     
            //   ff15????????         |                     
            //   8b0d????????         |                     
            //   89048de0654200       | mov                 dword ptr [ecx*4 + 0x4265e0], eax

    condition:
        7 of them and filesize < 376832
}