rule win_elirks_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.elirks."
        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.elirks"
        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 = { 8b4c240c 8d54240c 52 8d442418 50 51 8d942424030000 }
            // n = 7, score = 100
            //   8b4c240c             | mov                 ecx, dword ptr [esp + 0xc]
            //   8d54240c             | lea                 edx, [esp + 0xc]
            //   52                   | push                edx
            //   8d442418             | lea                 eax, [esp + 0x18]
            //   50                   | push                eax
            //   51                   | push                ecx
            //   8d942424030000       | lea                 edx, [esp + 0x324]

        $sequence_1 = { 83c40c c20400 8b44241c 8b4c2410 85c9 750a }
            // n = 6, score = 100
            //   83c40c               | add                 esp, 0xc
            //   c20400               | ret                 4
            //   8b44241c             | mov                 eax, dword ptr [esp + 0x1c]
            //   8b4c2410             | mov                 ecx, dword ptr [esp + 0x10]
            //   85c9                 | test                ecx, ecx
            //   750a                 | jne                 0xc

        $sequence_2 = { 33dd 03c3 8bd8 c1e304 8be8 c1ed05 }
            // n = 6, score = 100
            //   33dd                 | xor                 ebx, ebp
            //   03c3                 | add                 eax, ebx
            //   8bd8                 | mov                 ebx, eax
            //   c1e304               | shl                 ebx, 4
            //   8be8                 | mov                 ebp, eax
            //   c1ed05               | shr                 ebp, 5

        $sequence_3 = { 51 8d94248c040000 52 ff15???????? 8bd8 83fbff 895c2410 }
            // n = 7, score = 100
            //   51                   | push                ecx
            //   8d94248c040000       | lea                 edx, [esp + 0x48c]
            //   52                   | push                edx
            //   ff15????????         |                     
            //   8bd8                 | mov                 ebx, eax
            //   83fbff               | cmp                 ebx, -1
            //   895c2410             | mov                 dword ptr [esp + 0x10], ebx

        $sequence_4 = { 75d1 8bc6 5e 5d 5f c3 5e }
            // n = 7, score = 100
            //   75d1                 | jne                 0xffffffd3
            //   8bc6                 | mov                 eax, esi
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp
            //   5f                   | pop                 edi
            //   c3                   | ret                 
            //   5e                   | pop                 esi

        $sequence_5 = { 55 6a02 55 55 6800000040 8d442468 50 }
            // n = 7, score = 100
            //   55                   | push                ebp
            //   6a02                 | push                2
            //   55                   | push                ebp
            //   55                   | push                ebp
            //   6800000040           | push                0x40000000
            //   8d442468             | lea                 eax, [esp + 0x68]
            //   50                   | push                eax

        $sequence_6 = { eb14 80f940 7506 c6042a1a }
            // n = 4, score = 100
            //   eb14                 | jmp                 0x16
            //   80f940               | cmp                 cl, 0x40
            //   7506                 | jne                 8
            //   c6042a1a             | mov                 byte ptr [edx + ebp], 0x1a

        $sequence_7 = { 8b542424 890a 7e19 8b4d00 80393c 740f 83c101 }
            // n = 7, score = 100
            //   8b542424             | mov                 edx, dword ptr [esp + 0x24]
            //   890a                 | mov                 dword ptr [edx], ecx
            //   7e19                 | jle                 0x1b
            //   8b4d00               | mov                 ecx, dword ptr [ebp]
            //   80393c               | cmp                 byte ptr [ecx], 0x3c
            //   740f                 | je                  0x11
            //   83c101               | add                 ecx, 1

        $sequence_8 = { 8d54241c 52 50 56 55 }
            // n = 5, score = 100
            //   8d54241c             | lea                 edx, [esp + 0x1c]
            //   52                   | push                edx
            //   50                   | push                eax
            //   56                   | push                esi
            //   55                   | push                ebp

        $sequence_9 = { 56 8bf0 8b4604 33c9 898e00600000 25ffffff00 }
            // n = 6, score = 100
            //   56                   | push                esi
            //   8bf0                 | mov                 esi, eax
            //   8b4604               | mov                 eax, dword ptr [esi + 4]
            //   33c9                 | xor                 ecx, ecx
            //   898e00600000         | mov                 dword ptr [esi + 0x6000], ecx
            //   25ffffff00           | and                 eax, 0xffffff

    condition:
        7 of them and filesize < 81920
}