rule win_crenufs_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.crenufs."
        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.crenufs"
        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 = { 5f 5e 33c0 5b c20c00 8b4c2414 }
            // n = 6, score = 200
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   33c0                 | xor                 eax, eax
            //   5b                   | pop                 ebx
            //   c20c00               | ret                 0xc
            //   8b4c2414             | mov                 ecx, dword ptr [esp + 0x14]

        $sequence_1 = { 81ec24040000 53 56 57 ff7508 e8???????? 59 }
            // n = 7, score = 200
            //   81ec24040000         | sub                 esp, 0x424
            //   53                   | push                ebx
            //   56                   | push                esi
            //   57                   | push                edi
            //   ff7508               | push                dword ptr [ebp + 8]
            //   e8????????           |                     
            //   59                   | pop                 ecx

        $sequence_2 = { 85ff 7c24 8b06 ff501c 3bf8 7d1b 8b4638 }
            // n = 7, score = 200
            //   85ff                 | test                edi, edi
            //   7c24                 | jl                  0x26
            //   8b06                 | mov                 eax, dword ptr [esi]
            //   ff501c               | call                dword ptr [eax + 0x1c]
            //   3bf8                 | cmp                 edi, eax
            //   7d1b                 | jge                 0x1d
            //   8b4638               | mov                 eax, dword ptr [esi + 0x38]

        $sequence_3 = { e8???????? 8b4d1c 53 6880000000 }
            // n = 4, score = 200
            //   e8????????           |                     
            //   8b4d1c               | mov                 ecx, dword ptr [ebp + 0x1c]
            //   53                   | push                ebx
            //   6880000000           | push                0x80

        $sequence_4 = { 8d4d80 85c0 c645fc06 ff15???????? 56 8d4d90 }
            // n = 6, score = 200
            //   8d4d80               | lea                 ecx, [ebp - 0x80]
            //   85c0                 | test                eax, eax
            //   c645fc06             | mov                 byte ptr [ebp - 4], 6
            //   ff15????????         |                     
            //   56                   | push                esi
            //   8d4d90               | lea                 ecx, [ebp - 0x70]

        $sequence_5 = { c74204ffffffff 894210 894214 894218 }
            // n = 4, score = 200
            //   c74204ffffffff       | mov                 dword ptr [edx + 4], 0xffffffff
            //   894210               | mov                 dword ptr [edx + 0x10], eax
            //   894214               | mov                 dword ptr [edx + 0x14], eax
            //   894218               | mov                 dword ptr [edx + 0x18], eax

        $sequence_6 = { 753f 3bf6 753b 8b4604 }
            // n = 4, score = 200
            //   753f                 | jne                 0x41
            //   3bf6                 | cmp                 esi, esi
            //   753b                 | jne                 0x3d
            //   8b4604               | mov                 eax, dword ptr [esi + 4]

        $sequence_7 = { 50 ff15???????? 8d8560feffff 50 e8???????? 83c420 8d4de0 }
            // n = 7, score = 200
            //   50                   | push                eax
            //   ff15????????         |                     
            //   8d8560feffff         | lea                 eax, [ebp - 0x1a0]
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c420               | add                 esp, 0x20
            //   8d4de0               | lea                 ecx, [ebp - 0x20]

        $sequence_8 = { c645fc08 ff31 8d4de0 53 50 ff15???????? }
            // n = 6, score = 200
            //   c645fc08             | mov                 byte ptr [ebp - 4], 8
            //   ff31                 | push                dword ptr [ecx]
            //   8d4de0               | lea                 ecx, [ebp - 0x20]
            //   53                   | push                ebx
            //   50                   | push                eax
            //   ff15????????         |                     

        $sequence_9 = { 33c0 eb05 1bc0 83d8ff 5d 5b }
            // n = 6, score = 200
            //   33c0                 | xor                 eax, eax
            //   eb05                 | jmp                 7
            //   1bc0                 | sbb                 eax, eax
            //   83d8ff               | sbb                 eax, -1
            //   5d                   | pop                 ebp
            //   5b                   | pop                 ebx

    condition:
        7 of them and filesize < 106496
}