rule win_ascentloader_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.ascentloader."
        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.ascentloader"
        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 = { b8???????? eb0a b900240000 b8???????? }
            // n = 4, score = 100
            //   b8????????           |                     
            //   eb0a                 | jmp                 0xc
            //   b900240000           | mov                 ecx, 0x2400
            //   b8????????           |                     

        $sequence_1 = { 58 6a22 66894586 66898d76ffffff 66894d84 59 }
            // n = 6, score = 100
            //   58                   | pop                 eax
            //   6a22                 | push                0x22
            //   66894586             | mov                 word ptr [ebp - 0x7a], ax
            //   66898d76ffffff       | mov                 word ptr [ebp - 0x8a], cx
            //   66894d84             | mov                 word ptr [ebp - 0x7c], cx
            //   59                   | pop                 ecx

        $sequence_2 = { 6a65 58 88442427 33db 8844242d }
            // n = 5, score = 100
            //   6a65                 | push                0x65
            //   58                   | pop                 eax
            //   88442427             | mov                 byte ptr [esp + 0x27], al
            //   33db                 | xor                 ebx, ebx
            //   8844242d             | mov                 byte ptr [esp + 0x2d], al

        $sequence_3 = { 8b4dfc e8???????? 8b4df8 e8???????? 8b4df4 }
            // n = 5, score = 100
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]
            //   e8????????           |                     
            //   8b4df8               | mov                 ecx, dword ptr [ebp - 8]
            //   e8????????           |                     
            //   8b4df4               | mov                 ecx, dword ptr [ebp - 0xc]

        $sequence_4 = { 8955fc 83b88400000000 0f86ea000000 56 8bb080000000 }
            // n = 5, score = 100
            //   8955fc               | mov                 dword ptr [ebp - 4], edx
            //   83b88400000000       | cmp                 dword ptr [eax + 0x84], 0
            //   0f86ea000000         | jbe                 0xf0
            //   56                   | push                esi
            //   8bb080000000         | mov                 esi, dword ptr [eax + 0x80]

        $sequence_5 = { 53 53 8d45ec 8bf2 50 }
            // n = 5, score = 100
            //   53                   | push                ebx
            //   53                   | push                ebx
            //   8d45ec               | lea                 eax, [ebp - 0x14]
            //   8bf2                 | mov                 esi, edx
            //   50                   | push                eax

        $sequence_6 = { 57 68000000f0 6a01 33db 894de8 53 }
            // n = 6, score = 100
            //   57                   | push                edi
            //   68000000f0           | push                0xf0000000
            //   6a01                 | push                1
            //   33db                 | xor                 ebx, ebx
            //   894de8               | mov                 dword ptr [ebp - 0x18], ecx
            //   53                   | push                ebx

        $sequence_7 = { 83f8ff 7518 ff15???????? 57 ff15???????? ff15???????? e9???????? }
            // n = 7, score = 100
            //   83f8ff               | cmp                 eax, -1
            //   7518                 | jne                 0x1a
            //   ff15????????         |                     
            //   57                   | push                edi
            //   ff15????????         |                     
            //   ff15????????         |                     
            //   e9????????           |                     

        $sequence_8 = { 53 eb01 56 ff15???????? 6a50 }
            // n = 5, score = 100
            //   53                   | push                ebx
            //   eb01                 | jmp                 3
            //   56                   | push                esi
            //   ff15????????         |                     
            //   6a50                 | push                0x50

        $sequence_9 = { 8b5d10 56 8bf1 81e1ffff0000 c1ee10 83fb01 7531 }
            // n = 7, score = 100
            //   8b5d10               | mov                 ebx, dword ptr [ebp + 0x10]
            //   56                   | push                esi
            //   8bf1                 | mov                 esi, ecx
            //   81e1ffff0000         | and                 ecx, 0xffff
            //   c1ee10               | shr                 esi, 0x10
            //   83fb01               | cmp                 ebx, 1
            //   7531                 | jne                 0x33

    condition:
        7 of them and filesize < 253952
}