rule win_remus_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.remus."
        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.remus"
        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 = { 4989c1 4929d1 4983c1fe 4c8d442410 90 4c89ca 450fb610 }
            // n = 7, score = 100
            //   4989c1               | sar                 eax, 1
            //   4929d1               | ret                 
            //   4983c1fe             | dec                 eax
            //   4c8d442410           | mov                 eax, 0xfffffffe
            //   90                   | nop                 word ptr cs:[eax + eax]
            //   4c89ca               | inc                 cx
            //   450fb610             | cmp                 dword ptr [esp + eax + 2], 0

        $sequence_1 = { 4989f0 e8???????? 4883c420 4889f1 4883c104 4883e804 8b16 }
            // n = 7, score = 100
            //   4989f0               | dec                 ebp
            //   e8????????           |                     
            //   4883c420             | mov                 eax, edi
            //   4889f1               | inc                 ebp
            //   4883c104             | xor                 ecx, ecx
            //   4883e804             | dec                 eax
            //   8b16                 | lea                 ecx, [esp + 0x3a]

        $sequence_2 = { 4c89e9 e8???????? 4883bc24e800000000 0f84b4fdffff 4d85e4 0f84abfdffff }
            // n = 6, score = 100
            //   4c89e9               | dec                 esp
            //   e8????????           |                     
            //   4883bc24e800000000     | cmp    edi, dword ptr [esp + 0x28]
            //   0f84b4fdffff         | jbe                 0x2e7
            //   4d85e4               | inc                 esi
            //   0f84abfdffff         | movzx               esi, byte ptr [esi - 1]

        $sequence_3 = { 48c744242000000000 41b805000000 ba04000000 4531c9 e8???????? c744245000000000 }
            // n = 6, score = 100
            //   48c744242000000000     | dec    eax
            //   41b805000000         | cmp                 ecx, ebx
            //   ba04000000           | jae                 0xb5
            //   4531c9               | dec                 eax
            //   e8????????           |                     
            //   c744245000000000     | shl                 ebx, 3

        $sequence_4 = { 05e4fb1700 31c1 8b8424c0000000 8b8424c0000000 89c2 83e201 83f001 }
            // n = 7, score = 100
            //   05e4fb1700           | add                 esi, 0x43a90880
            //   31c1                 | inc                 esp
            //   8b8424c0000000       | and                 esi, ecx
            //   8b8424c0000000       | or                  esi, eax
            //   89c2                 | and                 esi, edx
            //   83e201               | not                 eax
            //   83f001               | dec                 eax

        $sequence_5 = { ba03000000 4989c0 4531c9 4889c7 e8???????? 4889f8 488b0d???????? }
            // n = 7, score = 100
            //   ba03000000           | mov                 eax, dword ptr [esp + 0x48]
            //   4989c0               | mov                 eax, dword ptr [esp + 0x48]
            //   4531c9               | mov                 eax, 0xde4f759b
            //   4889c7               | test                ecx, ecx
            //   e8????????           |                     
            //   4889f8               | jne                 0x4df
            //   488b0d????????       |                     

        $sequence_6 = { 4c89f9 4989d8 4531c9 e8???????? 4c89f9 4889fa }
            // n = 6, score = 100
            //   4c89f9               | mov                 ecx, ebx
            //   4989d8               | mov                 eax, dword ptr [esi + 0x24]
            //   4531c9               | dec                 eax
            //   e8????????           |                     
            //   4c89f9               | dec                 esp
            //   4889fa               | mov                 edx, ebp

        $sequence_7 = { 4885c9 740a 448b481c 41d1e9 448909 488b8c24b8000000 }
            // n = 6, score = 100
            //   4885c9               | mov                 eax, dword ptr [ebp - 8]
            //   740a                 | cmp                 eax, 0
            //   448b481c             | jne                 0x7a9
            //   41d1e9               | mov                 eax, dword ptr [ebp - 8]
            //   448909               | dec                 eax
            //   488b8c24b8000000     | add                 esp, 0x20

        $sequence_8 = { 8b8c2410030000 85c9 74cb 39c5 7469 c784241003000000000000 8b8c2410030000 }
            // n = 7, score = 100
            //   8b8c2410030000       | ja                  0x509
            //   85c9                 | nop                 word ptr cs:[eax + eax]
            //   74cb                 | mov                 eax, dword ptr [esp + 0xb0]
            //   39c5                 | dec                 eax
            //   7469                 | cwde                
            //   c784241003000000000000     | mov    ecx, dword ptr [esp + 0xb0]
            //   8b8c2410030000       | mov                 eax, dword ptr [esp + 0xb0]

        $sequence_9 = { 4c8b65d0 eb00 83f800 7509 488b5b08 e9???????? eb00 }
            // n = 7, score = 100
            //   4c8b65d0             | mov                 dword ptr [edx], ecx
            //   eb00                 | inc                 ecx
            //   83f800               | mov                 al, 1
            //   7509                 | mov                 ebp, 0xffffffff
            //   488b5b08             | dec                 esp
            //   e9????????           |                     
            //   eb00                 | mov                 ebx, ecx

    condition:
        7 of them and filesize < 475136
}