rule win_ranbyus_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.ranbyus."
        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.ranbyus"
        malpedia_rule_date = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        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 = { 8b442404 85c0 741b 8b4c2408 85c9 7413 8b4004 }
            // n = 7, score = 1100
            //   8b442404             | mov                 eax, dword ptr [esp + 4]
            //   85c0                 | test                eax, eax
            //   741b                 | je                  0x1d
            //   8b4c2408             | mov                 ecx, dword ptr [esp + 8]
            //   85c9                 | test                ecx, ecx
            //   7413                 | je                  0x15
            //   8b4004               | mov                 eax, dword ptr [eax + 4]

        $sequence_1 = { 89410b 8b4605 39780b 7407 }
            // n = 4, score = 1100
            //   89410b               | mov                 dword ptr [ecx + 0xb], eax
            //   8b4605               | mov                 eax, dword ptr [esi + 5]
            //   39780b               | cmp                 dword ptr [eax + 0xb], edi
            //   7407                 | je                  9

        $sequence_2 = { a3???????? 8b45e4 a3???????? 8a4576 a2???????? }
            // n = 5, score = 1100
            //   a3????????           |                     
            //   8b45e4               | mov                 eax, dword ptr [ebp - 0x1c]
            //   a3????????           |                     
            //   8a4576               | mov                 al, byte ptr [ebp + 0x76]
            //   a2????????           |                     

        $sequence_3 = { 85c0 745f 837c240400 7458 }
            // n = 4, score = 1100
            //   85c0                 | test                eax, eax
            //   745f                 | je                  0x61
            //   837c240400           | cmp                 dword ptr [esp + 4], 0
            //   7458                 | je                  0x5a

        $sequence_4 = { 8b44240c 85c0 745f 837c240400 7458 57 ff74240c }
            // n = 7, score = 1100
            //   8b44240c             | mov                 eax, dword ptr [esp + 0xc]
            //   85c0                 | test                eax, eax
            //   745f                 | je                  0x61
            //   837c240400           | cmp                 dword ptr [esp + 4], 0
            //   7458                 | je                  0x5a
            //   57                   | push                edi
            //   ff74240c             | push                dword ptr [esp + 0xc]

        $sequence_5 = { 8b742408 85f6 7505 83c8ff 5e c3 57 }
            // n = 7, score = 1100
            //   8b742408             | mov                 esi, dword ptr [esp + 8]
            //   85f6                 | test                esi, esi
            //   7505                 | jne                 7
            //   83c8ff               | or                  eax, 0xffffffff
            //   5e                   | pop                 esi
            //   c3                   | ret                 
            //   57                   | push                edi

        $sequence_6 = { 803845 7504 8bf0 ebeb 6a03 }
            // n = 5, score = 1100
            //   803845               | cmp                 byte ptr [eax], 0x45
            //   7504                 | jne                 6
            //   8bf0                 | mov                 esi, eax
            //   ebeb                 | jmp                 0xffffffed
            //   6a03                 | push                3

        $sequence_7 = { 89410b 8b4605 39780b 7407 c7401301000000 }
            // n = 5, score = 1100
            //   89410b               | mov                 dword ptr [ecx + 0xb], eax
            //   8b4605               | mov                 eax, dword ptr [esi + 5]
            //   39780b               | cmp                 dword ptr [eax + 0xb], edi
            //   7407                 | je                  9
            //   c7401301000000       | mov                 dword ptr [eax + 0x13], 1

        $sequence_8 = { e9???????? 47 e9???????? 0fb64e01 }
            // n = 4, score = 1100
            //   e9????????           |                     
            //   47                   | inc                 edi
            //   e9????????           |                     
            //   0fb64e01             | movzx               ecx, byte ptr [esi + 1]

        $sequence_9 = { 740b 3c7d 7407 6ae4 }
            // n = 4, score = 1100
            //   740b                 | je                  0xd
            //   3c7d                 | cmp                 al, 0x7d
            //   7407                 | je                  9
            //   6ae4                 | push                -0x1c

    condition:
        7 of them and filesize < 638976
}