rule win_nitol_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.nitol."
        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.nitol"
        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 = { 8dbd7cffffff 2bfe 8a06 3c2e 7503 ff45fc 837dfc03 }
            // n = 7, score = 200
            //   8dbd7cffffff         | lea                 edi, [ebp - 0x84]
            //   2bfe                 | sub                 edi, esi
            //   8a06                 | mov                 al, byte ptr [esi]
            //   3c2e                 | cmp                 al, 0x2e
            //   7503                 | jne                 5
            //   ff45fc               | inc                 dword ptr [ebp - 4]
            //   837dfc03             | cmp                 dword ptr [ebp - 4], 3

        $sequence_1 = { 8d44242c 55 50 53 8b5c241c 56 53 }
            // n = 7, score = 200
            //   8d44242c             | lea                 eax, [esp + 0x2c]
            //   55                   | push                ebp
            //   50                   | push                eax
            //   53                   | push                ebx
            //   8b5c241c             | mov                 ebx, dword ptr [esp + 0x1c]
            //   56                   | push                esi
            //   53                   | push                ebx

        $sequence_2 = { 53 56 57 e8???????? 33db a3???????? 3bc3 }
            // n = 7, score = 200
            //   53                   | push                ebx
            //   56                   | push                esi
            //   57                   | push                edi
            //   e8????????           |                     
            //   33db                 | xor                 ebx, ebx
            //   a3????????           |                     
            //   3bc3                 | cmp                 eax, ebx

        $sequence_3 = { 8d442430 55 bb7fffffff 50 53 }
            // n = 5, score = 200
            //   8d442430             | lea                 eax, [esp + 0x30]
            //   55                   | push                ebp
            //   bb7fffffff           | mov                 ebx, 0xffffff7f
            //   50                   | push                eax
            //   53                   | push                ebx

        $sequence_4 = { 50 ff15???????? 83c410 eb1c 8b45fc ff7485c4 8d8560ffffff }
            // n = 7, score = 200
            //   50                   | push                eax
            //   ff15????????         |                     
            //   83c410               | add                 esp, 0x10
            //   eb1c                 | jmp                 0x1e
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   ff7485c4             | push                dword ptr [ebp + eax*4 - 0x3c]
            //   8d8560ffffff         | lea                 eax, [ebp - 0xa0]

        $sequence_5 = { 6a28 e8???????? 59 40 50 8d8558f7ffff }
            // n = 6, score = 200
            //   6a28                 | push                0x28
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   40                   | inc                 eax
            //   50                   | push                eax
            //   8d8558f7ffff         | lea                 eax, [ebp - 0x8a8]

        $sequence_6 = { e9???????? 8b8688000000 33ed 83c014 85c0 7e7f }
            // n = 6, score = 200
            //   e9????????           |                     
            //   8b8688000000         | mov                 eax, dword ptr [esi + 0x88]
            //   33ed                 | xor                 ebp, ebp
            //   83c014               | add                 eax, 0x14
            //   85c0                 | test                eax, eax
            //   7e7f                 | jle                 0x81

        $sequence_7 = { 83650c00 6a0a 8d4dc0 e8???????? 8365fc00 e8???????? 8b4004 }
            // n = 7, score = 200
            //   83650c00             | and                 dword ptr [ebp + 0xc], 0
            //   6a0a                 | push                0xa
            //   8d4dc0               | lea                 ecx, [ebp - 0x40]
            //   e8????????           |                     
            //   8365fc00             | and                 dword ptr [ebp - 4], 0
            //   e8????????           |                     
            //   8b4004               | mov                 eax, dword ptr [eax + 4]

        $sequence_8 = { c645dddb c645dec1 c645dfda c645e09d c645e1fe c645e29f c645e3c1 }
            // n = 7, score = 200
            //   c645dddb             | mov                 byte ptr [ebp - 0x23], 0xdb
            //   c645dec1             | mov                 byte ptr [ebp - 0x22], 0xc1
            //   c645dfda             | mov                 byte ptr [ebp - 0x21], 0xda
            //   c645e09d             | mov                 byte ptr [ebp - 0x20], 0x9d
            //   c645e1fe             | mov                 byte ptr [ebp - 0x1f], 0xfe
            //   c645e29f             | mov                 byte ptr [ebp - 0x1e], 0x9f
            //   c645e3c1             | mov                 byte ptr [ebp - 0x1d], 0xc1

        $sequence_9 = { 50 e8???????? 83c40c 33db 6a01 53 53 }
            // n = 7, score = 200
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   33db                 | xor                 ebx, ebx
            //   6a01                 | push                1
            //   53                   | push                ebx
            //   53                   | push                ebx

    condition:
        7 of them and filesize < 139264
}