rule win_alphanc_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-05-16"
        version = "1"
        description = "Detects win.alphanc."
        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.alphanc"
        malpedia_rule_date = "20220513"
        malpedia_hash = "7f4b2229e6ae614d86d74917f6d5b41890e62a26"
        malpedia_version = "20220516"
        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 = { 8b5040 85c9 7506 b801000000 c3 56 8b31 }
            // n = 7, score = 100
            //   8b5040               | mov                 edx, dword ptr [eax + 0x40]
            //   85c9                 | test                ecx, ecx
            //   7506                 | jne                 8
            //   b801000000           | mov                 eax, 1
            //   c3                   | ret                 
            //   56                   | push                esi
            //   8b31                 | mov                 esi, dword ptr [ecx]

        $sequence_1 = { 85c9 7503 5f 5e c3 8b5704 52 }
            // n = 7, score = 100
            //   85c9                 | test                ecx, ecx
            //   7503                 | jne                 5
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   c3                   | ret                 
            //   8b5704               | mov                 edx, dword ptr [edi + 4]
            //   52                   | push                edx

        $sequence_2 = { 8b742408 85f6 7451 56 e8???????? 8d86cc000000 6a20 }
            // n = 7, score = 100
            //   8b742408             | mov                 esi, dword ptr [esp + 8]
            //   85f6                 | test                esi, esi
            //   7451                 | je                  0x53
            //   56                   | push                esi
            //   e8????????           |                     
            //   8d86cc000000         | lea                 eax, [esi + 0xcc]
            //   6a20                 | push                0x20

        $sequence_3 = { 8bf0 85f6 89742410 0f84ba000000 6819010000 68???????? 6a0c }
            // n = 7, score = 100
            //   8bf0                 | mov                 esi, eax
            //   85f6                 | test                esi, esi
            //   89742410             | mov                 dword ptr [esp + 0x10], esi
            //   0f84ba000000         | je                  0xc0
            //   6819010000           | push                0x119
            //   68????????           |                     
            //   6a0c                 | push                0xc

        $sequence_4 = { 5e 668901 b8de750000 87e5 87e5 87e5 89e5 }
            // n = 7, score = 100
            //   5e                   | pop                 esi
            //   668901               | mov                 word ptr [ecx], ax
            //   b8de750000           | mov                 eax, 0x75de
            //   87e5                 | xchg                ebp, esp
            //   87e5                 | xchg                ebp, esp
            //   87e5                 | xchg                ebp, esp
            //   89e5                 | mov                 ebp, esp

        $sequence_5 = { bf01000000 e9???????? 68c6030000 68???????? 6a65 6a71 6a10 }
            // n = 7, score = 100
            //   bf01000000           | mov                 edi, 1
            //   e9????????           |                     
            //   68c6030000           | push                0x3c6
            //   68????????           |                     
            //   6a65                 | push                0x65
            //   6a71                 | push                0x71
            //   6a10                 | push                0x10

        $sequence_6 = { 85c0 7d07 5f 5e 5d 33c0 5b }
            // n = 7, score = 100
            //   85c0                 | test                eax, eax
            //   7d07                 | jge                 9
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp
            //   33c0                 | xor                 eax, eax
            //   5b                   | pop                 ebx

        $sequence_7 = { 6881000000 50 e8???????? 83c410 85ff 7444 8b4e10 }
            // n = 7, score = 100
            //   6881000000           | push                0x81
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10
            //   85ff                 | test                edi, edi
            //   7444                 | je                  0x46
            //   8b4e10               | mov                 ecx, dword ptr [esi + 0x10]

        $sequence_8 = { 52 e8???????? 8b33 83c404 f6460c04 7471 8b442478 }
            // n = 7, score = 100
            //   52                   | push                edx
            //   e8????????           |                     
            //   8b33                 | mov                 esi, dword ptr [ebx]
            //   83c404               | add                 esp, 4
            //   f6460c04             | test                byte ptr [esi + 0xc], 4
            //   7471                 | je                  0x73
            //   8b442478             | mov                 eax, dword ptr [esp + 0x78]

        $sequence_9 = { 8b8588000000 3bc7 740f 50 e8???????? 83c404 89bd88000000 }
            // n = 7, score = 100
            //   8b8588000000         | mov                 eax, dword ptr [ebp + 0x88]
            //   3bc7                 | cmp                 eax, edi
            //   740f                 | je                  0x11
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   89bd88000000         | mov                 dword ptr [ebp + 0x88], edi

    condition:
        7 of them and filesize < 2015232
}