rule win_rarstar_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.rarstar."
        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.rarstar"
        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 = { 745f 50 c705????????01000000 e8???????? }
            // n = 4, score = 100
            //   745f                 | je                  0x61
            //   50                   | push                eax
            //   c705????????01000000     |     
            //   e8????????           |                     

        $sequence_1 = { 8a1c29 8d4601 25ff000080 7907 48 }
            // n = 5, score = 100
            //   8a1c29               | mov                 bl, byte ptr [ecx + ebp]
            //   8d4601               | lea                 eax, [esi + 1]
            //   25ff000080           | and                 eax, 0x800000ff
            //   7907                 | jns                 9
            //   48                   | dec                 eax

        $sequence_2 = { 3bee 0f8485000000 8b442410 8bfd }
            // n = 4, score = 100
            //   3bee                 | cmp                 ebp, esi
            //   0f8485000000         | je                  0x8b
            //   8b442410             | mov                 eax, dword ptr [esp + 0x10]
            //   8bfd                 | mov                 edi, ebp

        $sequence_3 = { 53 56 57 8365d800 c745dc94254000 }
            // n = 5, score = 100
            //   53                   | push                ebx
            //   56                   | push                esi
            //   57                   | push                edi
            //   8365d800             | and                 dword ptr [ebp - 0x28], 0
            //   c745dc94254000       | mov                 dword ptr [ebp - 0x24], 0x402594

        $sequence_4 = { c3 395c2414 7405 be01000000 }
            // n = 4, score = 100
            //   c3                   | ret                 
            //   395c2414             | cmp                 dword ptr [esp + 0x14], ebx
            //   7405                 | je                  7
            //   be01000000           | mov                 esi, 1

        $sequence_5 = { 81ce00ffffff 46 89b42424030000 8a10 8d743420 }
            // n = 5, score = 100
            //   81ce00ffffff         | or                  esi, 0xffffff00
            //   46                   | inc                 esi
            //   89b42424030000       | mov                 dword ptr [esp + 0x324], esi
            //   8a10                 | mov                 dl, byte ptr [eax]
            //   8d743420             | lea                 esi, [esp + esi + 0x20]

        $sequence_6 = { c1e902 83e203 83f908 7229 f3a5 ff2495c86c4000 8bc7 }
            // n = 7, score = 100
            //   c1e902               | shr                 ecx, 2
            //   83e203               | and                 edx, 3
            //   83f908               | cmp                 ecx, 8
            //   7229                 | jb                  0x2b
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   ff2495c86c4000       | jmp                 dword ptr [edx*4 + 0x406cc8]
            //   8bc7                 | mov                 eax, edi

        $sequence_7 = { 55 56 57 b940000000 33c0 8d7c2424 }
            // n = 6, score = 100
            //   55                   | push                ebp
            //   56                   | push                esi
            //   57                   | push                edi
            //   b940000000           | mov                 ecx, 0x40
            //   33c0                 | xor                 eax, eax
            //   8d7c2424             | lea                 edi, [esp + 0x24]

        $sequence_8 = { 745f 50 c705????????01000000 e8???????? 8b742424 8bc8 d1e1 }
            // n = 7, score = 100
            //   745f                 | je                  0x61
            //   50                   | push                eax
            //   c705????????01000000     |     
            //   e8????????           |                     
            //   8b742424             | mov                 esi, dword ptr [esp + 0x24]
            //   8bc8                 | mov                 ecx, eax
            //   d1e1                 | shl                 ecx, 1

        $sequence_9 = { 8d4c2424 51 8d942484000000 6800100000 52 50 ffd5 }
            // n = 7, score = 100
            //   8d4c2424             | lea                 ecx, [esp + 0x24]
            //   51                   | push                ecx
            //   8d942484000000       | lea                 edx, [esp + 0x84]
            //   6800100000           | push                0x1000
            //   52                   | push                edx
            //   50                   | push                eax
            //   ffd5                 | call                ebp

    condition:
        7 of them and filesize < 122880
}