rule win_vshell_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.vshell."
        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.vshell"
        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 = { e8???????? c700b4230000 e8???????? 4889c1 4889df 488d059f3b4f00 488b5c2430 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   c700b4230000         | lea                 ecx, [0x983f5f]
            //   e8????????           |                     
            //   4889c1               | dec                 eax
            //   4889df               | mov                 eax, dword ptr [esp + 0x60]
            //   488d059f3b4f00       | dec                 eax
            //   488b5c2430           | mov                 dword ptr [eax + 0x2b0], ecx

        $sequence_1 = { e9???????? 488b842498000000 0fb65c2436 e8???????? 0fb6442435 488b4c2440 e9???????? }
            // n = 7, score = 100
            //   e9????????           |                     
            //   488b842498000000     | dec                 eax
            //   0fb65c2436           | lea                 eax, [0x3f40ec]
            //   e8????????           |                     
            //   0fb6442435           | dec                 eax
            //   488b4c2440           | mov                 dword ptr [esp + 0x28], eax
            //   e9????????           |                     

        $sequence_2 = { e9???????? 4983f803 755b 4c8d4303 4c39c6 733d 4c898424e0000000 }
            // n = 7, score = 100
            //   e9????????           |                     
            //   4983f803             | nop                 
            //   755b                 | call                ecx
            //   4c8d4303             | dec                 eax
            //   4c39c6               | mov                 ecx, dword ptr [eax]
            //   733d                 | dec                 eax
            //   4c898424e0000000     | mov                 edx, eax

        $sequence_3 = { e8???????? 4889c1 4889df 488d05c1aa4f00 488b5c2430 e8???????? c700d9220000 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   4889c1               | mov                 byte ptr [eax + 0x35], dl
            //   4889df               | movzx               edx, byte ptr [esp + 0xad]
            //   488d05c1aa4f00       | inc                 esp
            //   488b5c2430           | movzx               eax, byte ptr [esp + 0xc6]
            //   e8????????           |                     
            //   c700d9220000         | inc                 esp

        $sequence_4 = { e8???????? 66480f7ec0 0f1f440000 e8???????? 4889c3 488d05b1463500 eb29 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   66480f7ec0           | dec                 eax
            //   0f1f440000           | cmp                 edx, 0xf
            //   e8????????           |                     
            //   4889c3               | jae                 0x89c
            //   488d05b1463500       | inc                 esp
            //   eb29                 | movzx               eax, byte ptr [esp + edx + 0x19]

        $sequence_5 = { eb17 440fb64c3c19 4131f1 44884c1419 4488443c19 4883c002 483d90000000 }
            // n = 7, score = 100
            //   eb17                 | lea                 eax, [ebx + 3]
            //   440fb64c3c19         | dec                 esp
            //   4131f1               | cmp                 esi, eax
            //   44884c1419           | mov                 ecx, 9
            //   4488443c19           | nop                 
            //   4883c002             | dec                 esp
            //   483d90000000         | lea                 eax, [ebx + 3]

        $sequence_6 = { c644242f5a 48bad793ed84f6cb493c 488954241e c64424263d 31c0 6690 eb14 }
            // n = 7, score = 100
            //   c644242f5a           | xor                 edx, eax
            //   48bad793ed84f6cb493c     | mov    byte ptr [eax + 7], dl
            //   488954241e           | movzx               edx, byte ptr [esp + 0x50]
            //   c64424263d           | inc                 esp
            //   31c0                 | movzx               eax, byte ptr [esp + 0x4b]
            //   6690                 | mov                 byte ptr [eax + 6], dl
            //   eb14                 | movzx               edx, byte ptr [esp + 0x5e]

        $sequence_7 = { e9???????? 4983f804 7545 4c8d4301 4c39c6 7331 488d0565834400 }
            // n = 7, score = 100
            //   e9????????           |                     
            //   4983f804             | dec                 eax
            //   7545                 | mov                 edx, eax
            //   4c8d4301             | mov                 eax, 0xffffffe7
            //   4c39c6               | call                ecx
            //   7331                 | dec                 eax
            //   488d0565834400       | mov                 ecx, dword ptr [esp + 0x28]

        $sequence_8 = { e8???????? 90 89442408 48895c2410 0f1f440000 e8???????? 8b442408 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   90                   | nop                 
            //   89442408             | dec                 eax
            //   48895c2410           | mov                 ecx, dword ptr [esp + 0x148]
            //   0f1f440000           | xor                 eax, eax
            //   e8????????           |                     
            //   8b442408             | jmp                 0x1704

        $sequence_9 = { e8???????? 84c0 0f84b7000000 e8???????? 48898424d8000000 48899c2488000000 488d0550f69800 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   84c0                 | je                  0x3e2
            //   0f84b7000000         | nop                 
            //   e8????????           |                     
            //   48898424d8000000     | movzx               ecx, byte ptr [esp + 0x71]
            //   48899c2488000000     | movzx               ecx, cl
            //   488d0550f69800       | mov                 byte ptr [esp + 0x2e], cl

    condition:
        7 of them and filesize < 39452672
}