rule win_acbackdoor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.acbackdoor."
        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.acbackdoor"
        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 = { c744240c801e4b00 89742408 89442404 c70424???????? e8???????? e9???????? 8b842408020000 }
            // n = 7, score = 100
            //   c744240c801e4b00     | mov                 dword ptr [esp + 0xc], 0x4b1e80
            //   89742408             | mov                 dword ptr [esp + 8], esi
            //   89442404             | mov                 dword ptr [esp + 4], eax
            //   c70424????????       |                     
            //   e8????????           |                     
            //   e9????????           |                     
            //   8b842408020000       | mov                 eax, dword ptr [esp + 0x208]

        $sequence_1 = { 89c1 c1e918 0fca 88633a 884b38 89c1 c1e910 }
            // n = 7, score = 100
            //   89c1                 | mov                 ecx, eax
            //   c1e918               | shr                 ecx, 0x18
            //   0fca                 | bswap               edx
            //   88633a               | mov                 byte ptr [ebx + 0x3a], ah
            //   884b38               | mov                 byte ptr [ebx + 0x38], cl
            //   89c1                 | mov                 ecx, eax
            //   c1e910               | shr                 ecx, 0x10

        $sequence_2 = { 8b4c2448 8d742448 894844 8b7c242c 8b4c3c44 894c3afc 8d4848 }
            // n = 7, score = 100
            //   8b4c2448             | mov                 ecx, dword ptr [esp + 0x48]
            //   8d742448             | lea                 esi, [esp + 0x48]
            //   894844               | mov                 dword ptr [eax + 0x44], ecx
            //   8b7c242c             | mov                 edi, dword ptr [esp + 0x2c]
            //   8b4c3c44             | mov                 ecx, dword ptr [esp + edi + 0x44]
            //   894c3afc             | mov                 dword ptr [edx + edi - 4], ecx
            //   8d4848               | lea                 ecx, [eax + 0x48]

        $sequence_3 = { e8???????? 85c0 7594 896c2404 893424 e8???????? c744240448000000 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   85c0                 | test                eax, eax
            //   7594                 | jne                 0xffffff96
            //   896c2404             | mov                 dword ptr [esp + 4], ebp
            //   893424               | mov                 dword ptr [esp], esi
            //   e8????????           |                     
            //   c744240448000000     | mov                 dword ptr [esp + 4], 0x48

        $sequence_4 = { c70000000000 85d2 743f 31db bf80ffffff 31c0 90 }
            // n = 7, score = 100
            //   c70000000000         | mov                 dword ptr [eax], 0
            //   85d2                 | test                edx, edx
            //   743f                 | je                  0x41
            //   31db                 | xor                 ebx, ebx
            //   bf80ffffff           | mov                 edi, 0xffffff80
            //   31c0                 | xor                 eax, eax
            //   90                   | nop                 

        $sequence_5 = { 8b07 31db 8986f8050000 e9???????? 8b2f 8bbef0090000 85ed }
            // n = 7, score = 100
            //   8b07                 | mov                 eax, dword ptr [edi]
            //   31db                 | xor                 ebx, ebx
            //   8986f8050000         | mov                 dword ptr [esi + 0x5f8], eax
            //   e9????????           |                     
            //   8b2f                 | mov                 ebp, dword ptr [edi]
            //   8bbef0090000         | mov                 edi, dword ptr [esi + 0x9f0]
            //   85ed                 | test                ebp, ebp

        $sequence_6 = { c7831c060000c8000000 c783140a000000000000 c783440a000060ea0000 c783280a000005000000 c7832406000076000000 818b5c0a000010000040 c7830008000002000000 }
            // n = 7, score = 100
            //   c7831c060000c8000000     | mov    dword ptr [ebx + 0x61c], 0xc8
            //   c783140a000000000000     | mov    dword ptr [ebx + 0xa14], 0
            //   c783440a000060ea0000     | mov    dword ptr [ebx + 0xa44], 0xea60
            //   c783280a000005000000     | mov    dword ptr [ebx + 0xa28], 5
            //   c7832406000076000000     | mov    dword ptr [ebx + 0x624], 0x76
            //   818b5c0a000010000040     | or    dword ptr [ebx + 0xa5c], 0x40000010
            //   c7830008000002000000     | mov    dword ptr [ebx + 0x800], 2

        $sequence_7 = { e8???????? c7442404???????? 89442408 891c24 e8???????? e9???????? e8???????? }
            // n = 7, score = 100
            //   e8????????           |                     
            //   c7442404????????     |                     
            //   89442408             | mov                 dword ptr [esp + 8], eax
            //   891c24               | mov                 dword ptr [esp], ebx
            //   e8????????           |                     
            //   e9????????           |                     
            //   e8????????           |                     

        $sequence_8 = { c744240800000000 897c2404 e8???????? 89c3 85c0 7589 c70424???????? }
            // n = 7, score = 100
            //   c744240800000000     | mov                 dword ptr [esp + 8], 0
            //   897c2404             | mov                 dword ptr [esp + 4], edi
            //   e8????????           |                     
            //   89c3                 | mov                 ebx, eax
            //   85c0                 | test                eax, eax
            //   7589                 | jne                 0xffffff8b
            //   c70424????????       |                     

        $sequence_9 = { c744240c2b0c0000 c7442408???????? c744240401000000 891c24 e8???????? e9???????? c6400700 }
            // n = 7, score = 100
            //   c744240c2b0c0000     | mov                 dword ptr [esp + 0xc], 0xc2b
            //   c7442408????????     |                     
            //   c744240401000000     | mov                 dword ptr [esp + 4], 1
            //   891c24               | mov                 dword ptr [esp], ebx
            //   e8????????           |                     
            //   e9????????           |                     
            //   c6400700             | mov                 byte ptr [eax + 7], 0

    condition:
        7 of them and filesize < 1704960
}