rule win_rhysida_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.rhysida."
        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.rhysida"
        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 = { f6c201 4989cc 89d5 4d89c6 750a 83790801 0f8483020000 }
            // n = 7, score = 400
            //   f6c201               | mov                 edx, 2
            //   4989cc               | dec                 eax
            //   89d5                 | mov                 ecx, eax
            //   4d89c6               | mov                 dword ptr [ebp - 0x44], eax
            //   750a                 | dec                 eax
            //   83790801             | lea                 eax, [ebp - 0x60]
            //   0f8483020000         | dec                 eax

        $sequence_1 = { 4889c2 488b4510 4801d0 0fb6400c 3c01 7504 8345c001 }
            // n = 7, score = 400
            //   4889c2               | inc                 cx
            //   488b4510             | movq                mm1, qword ptr [esp + eax]
            //   4801d0               | movups              xmmword ptr [edx + eax], xmm1
            //   0fb6400c             | dec                 eax
            //   3c01                 | add                 eax, 0x10
            //   7504                 | inc                 ebp
            //   8345c001             | cmp                 ebp, edx

        $sequence_2 = { 4489d8 448d5001 4539ca 44899308010000 c684038800000000 4489d0 7374 }
            // n = 7, score = 400
            //   4489d8               | ret                 
            //   448d5001             | dec                 eax
            //   4539ca               | lea                 edx, [0x3da24]
            //   44899308010000       | dec                 eax
            //   c684038800000000     | lea                 ecx, [0x3da33]
            //   4489d0               | inc                 ecx
            //   7374                 | pop                 esp

        $sequence_3 = { f0832b01 448b23 488b3d???????? 4889f1 ffd7 31c0 4585e4 }
            // n = 7, score = 400
            //   f0832b01             | lea                 ecx, [0x5458f]
            //   448b23               | inc                 ecx
            //   488b3d????????       |                     
            //   4889f1               | mov                 eax, 0x86
            //   ffd7                 | nop                 
            //   31c0                 | nop                 dword ptr [eax + eax]
            //   4585e4               | ret                 

        $sequence_4 = { c785cc01000001000000 c785c801000000000000 c785c401000000000000 c785c001000000000000 c785b801000000000000 488b85e0010000 488b5078 }
            // n = 7, score = 400
            //   c785cc01000001000000     | mov    edx, dword ptr [ebp - 0xc]
            //   c785c801000000000000     | mov    eax, dword ptr [ebp - 0xc]
            //   c785c401000000000000     | sub    edx, eax
            //   c785c001000000000000     | mov    eax, edx
            //   c785b801000000000000     | mov    dword ptr [ebp - 0x2c], eax
            //   488b85e0010000       | dec                 eax
            //   488b5078             | mov                 dword ptr [ebp - 0x20], 0

        $sequence_5 = { 8d4303 8d5003 85c0 0f48c2 c1f802 89c2 89d0 }
            // n = 7, score = 400
            //   8d4303               | dec                 eax
            //   8d5003               | add                 eax, edx
            //   85c0                 | dec                 eax
            //   0f48c2               | mov                 ecx, eax
            //   c1f802               | mov                 dword ptr [ebp - 0x24], eax
            //   89c2                 | mov                 eax, dword ptr [ebp - 4]
            //   89d0                 | dec                 eax

        $sequence_6 = { 8b5558 89542420 4589c1 4189c8 89c2 488b4d10 e8???????? }
            // n = 7, score = 400
            //   8b5558               | jne                 0xb8b
            //   89542420             | dec                 eax
            //   4589c1               | mov                 edx, dword ptr [esi + 8]
            //   4189c8               | dec                 eax
            //   89c2                 | mov                 ecx, dword ptr [edi + 8]
            //   488b4d10             | call                dword ptr [ebp + 0x30]
            //   e8????????           |                     

        $sequence_7 = { 4983c208 488b8424b0000000 4d8b29 49f762f8 31ff 4c01c0 4811fa }
            // n = 7, score = 400
            //   4983c208             | dec                 ecx
            //   488b8424b0000000     | mov                 ecx, edx
            //   4d8b29               | inc                 ecx
            //   49f762f8             | mov                 eax, 1
            //   31ff                 | mov                 edx, 4
            //   4c01c0               | dec                 eax
            //   4811fa               | mov                 ecx, eax

        $sequence_8 = { c785f810000000000000 e9???????? c785f010000000000000 e9???????? 8b85f4100000 c1e004 89c2 }
            // n = 7, score = 400
            //   c785f810000000000000     | dec    eax
            //   e9????????           |                     
            //   c785f010000000000000     | add    eax, edx
            //   e9????????           |                     
            //   8b85f4100000         | movzx               edx, byte ptr [eax]
            //   c1e004               | mov                 eax, dword ptr [ebp - 4]
            //   89c2                 | dec                 eax

        $sequence_9 = { 85c0 89c3 7414 89d8 4881c4a0010000 5b 5e }
            // n = 7, score = 400
            //   85c0                 | cmp                 edi, 5
            //   89c3                 | je                  0xbe9
            //   7414                 | inc                 ecx
            //   89d8                 | cmp                 edi, 6
            //   4881c4a0010000       | je                  0xbcd
            //   5b                   | je                  0xc32
            //   5e                   | inc                 ebp

    condition:
        7 of them and filesize < 2369536
}