rule win_ascentloader_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        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 = "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 = { 8bce e8???????? 83c41c 8945f4 83f8ff }
            // n = 5, score = 100
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   83c41c               | add                 esp, 0x1c
            //   8945f4               | mov                 dword ptr [ebp - 0xc], eax
            //   83f8ff               | cmp                 eax, -1

        $sequence_1 = { 6a0a 5a 6689442428 e8???????? 53 ff15???????? }
            // n = 6, score = 100
            //   6a0a                 | push                0xa
            //   5a                   | pop                 edx
            //   6689442428           | mov                 word ptr [esp + 0x28], ax
            //   e8????????           |                     
            //   53                   | push                ebx
            //   ff15????????         |                     

        $sequence_2 = { 8bf8 897dd8 85ff 7516 83c8ff e9???????? c745e440ac4100 }
            // n = 7, score = 100
            //   8bf8                 | mov                 edi, eax
            //   897dd8               | mov                 dword ptr [ebp - 0x28], edi
            //   85ff                 | test                edi, edi
            //   7516                 | jne                 0x18
            //   83c8ff               | or                  eax, 0xffffffff
            //   e9????????           |                     
            //   c745e440ac4100       | mov                 dword ptr [ebp - 0x1c], 0x41ac40

        $sequence_3 = { 8d45e0 884dc9 50 57 ff15???????? 6a03 6a01 }
            // n = 7, score = 100
            //   8d45e0               | lea                 eax, [ebp - 0x20]
            //   884dc9               | mov                 byte ptr [ebp - 0x37], cl
            //   50                   | push                eax
            //   57                   | push                edi
            //   ff15????????         |                     
            //   6a03                 | push                3
            //   6a01                 | push                1

        $sequence_4 = { 8945f4 85f6 740f 56 ff15???????? }
            // n = 5, score = 100
            //   8945f4               | mov                 dword ptr [ebp - 0xc], eax
            //   85f6                 | test                esi, esi
            //   740f                 | je                  0x11
            //   56                   | push                esi
            //   ff15????????         |                     

        $sequence_5 = { 56 8d7107 57 50 8bd6 8975f8 8d4df8 }
            // n = 7, score = 100
            //   56                   | push                esi
            //   8d7107               | lea                 esi, [ecx + 7]
            //   57                   | push                edi
            //   50                   | push                eax
            //   8bd6                 | mov                 edx, esi
            //   8975f8               | mov                 dword ptr [ebp - 8], esi
            //   8d4df8               | lea                 ecx, [ebp - 8]

        $sequence_6 = { 57 68???????? 8bf9 ff15???????? 6a53 }
            // n = 5, score = 100
            //   57                   | push                edi
            //   68????????           |                     
            //   8bf9                 | mov                 edi, ecx
            //   ff15????????         |                     
            //   6a53                 | push                0x53

        $sequence_7 = { 33c9 5a 8d4161 88440da0 }
            // n = 4, score = 100
            //   33c9                 | xor                 ecx, ecx
            //   5a                   | pop                 edx
            //   8d4161               | lea                 eax, [ecx + 0x61]
            //   88440da0             | mov                 byte ptr [ebp + ecx - 0x60], al

        $sequence_8 = { 6689459e 668945a4 58 668945a8 }
            // n = 4, score = 100
            //   6689459e             | mov                 word ptr [ebp - 0x62], ax
            //   668945a4             | mov                 word ptr [ebp - 0x5c], ax
            //   58                   | pop                 eax
            //   668945a8             | mov                 word ptr [ebp - 0x58], ax

        $sequence_9 = { 8b55f0 33c9 83faff 0f44c1 }
            // n = 4, score = 100
            //   8b55f0               | mov                 edx, dword ptr [ebp - 0x10]
            //   33c9                 | xor                 ecx, ecx
            //   83faff               | cmp                 edx, -1
            //   0f44c1               | cmove               eax, ecx

    condition:
        7 of them and filesize < 253952
}